
NSCA's Guide to Tests and Assessments
Edited by Todd A. Miller and NSCA -National Strength & Conditioning Association
Series: NSCA Science of Strength & Conditioning
368 Pages
NSCA's Guide to Tests and Assessments offers strength and conditioning professionals a one-stop resource for the best research-supported fitness and performance measures available. Created by top experts in the National Strength and Conditioning Association (NSCA), this comprehensive text offers extensive information on which factors matter and how to evaluate them as accurately and easily as possible. Editor Todd Miller and an authoritative team of contributors have compiled an exceptional reference and valuable tool for practicing professionals and an indispensable educational resource for students.
NSCA's Guide to Tests and Assessments presents the latest research from respected scientists and practitioners in exercise testing and assessment. The text begins with an introduction to testing, data analysis, and formulating conclusions. It then features a by-chapter presentation of tests and assessments for body composition, heart rate and blood pressure, metabolic rate, aerobic power, lactate threshold, muscular strength, muscular endurance, power, speed and agility, mobility, and balance and stability. Using descriptions of multiple test options for each key fitness component, readers will learn to choose from a range of alternatives to meet the needs of their athletes, reach training objectives, choose from available equipment, and work within budgets.
Each chapter provides a summary detailing the key testing and assessment information for each fitness component, the equipment needed for performing the tests, step-by-step instructions, normative data for the tests, and multiple test options per conditioning component. Insights into the applications of testing for certain fitness components are also presented:
• The value of body composition assessments in determining health and fitness levels for competitive athletes as well as individuals across the life span
• How an understanding of 24-hour energy expenditure can be useful in structuring a complete diet and exercise plan for weight loss, gain, or maintenance
• How to select a maximal or submaximal aerobic power test that is specific to the demands of a client’s or athlete’s sport
• Discussion of the mechanical and physiological factors shown to influence the expression of muscular strength
• An examination of the relevant factors influencing power production and explosive movement capacity
• Differences between mobility and flexibility and a discussion of the acute versus chronic effects of static stretching
• Theories and concepts of balance and stability, their effects on performance, and categories of testing for balance and stability
NSCA's Guide to Tests and Assessments also includes NSCA-approved testing protocols, extensive references to current research, and applications for the testing of conditioning components. Information is presented in an accessible manner to help explain the findings of both researchers and practitioners so that readers can select the most effective and efficient approach for athlete and client assessments.
Properly conducted tests and skillful assessment of data enable fitness professionals to develop individualized training programs based on their clients’ or athletes’ physiological and functional capacities. Credible,, current, and complete, NSCA's Guide to Tests and Assessments provides a clear understanding of the test selection process, how to implement appropriate data collection, and how to analyze data to make appropriate training decisions that will help athletes and clients achieve their performance goals.
NSCA’s Guide to Tests and Assessments is part of the Science of Strength and Conditioning series. Developed with the expertise of the National Strength and Conditioning Association (NSCA), this series of texts provides the guidelines for converting scientific research into practical application. The series covers topics such as tests and assessments, program design, and nutrition.
Earn continuing education credits/units! A continuing education course and exam that uses this book is also available. It may be purchased separately or as part of a package that includes all the course materials and exam.
Chapter 1: Tests, Data Analysis, and Conclusions
Matt Rhea, PhD, and Mark Peterson, PhD
Screening Tests
Data Evaluation and Statistical Analysis
Normalizing of Fitness Data
Tracking Data Over Time
Summary
Chapter 2: Body Composition
Nick Ratamess, PhD
Sport Performance and Body Composition
Body Composition Measurement
Measuring Height, Body Weight, and Body Mass Index
Body Fat Standards
Comparison of Body Composition Techniques
Summary
Chapter 3: Heart Rate and Blood Pressure
Dan Drury, DPE
Heart Rate Control
Exercise Intensity and Heart Rate
Sport Performance and Heart Rate
Heart Rate Measurement
Blood Pressure
Summary
Chapter 4: Metabolic Rate
Wayne Miller, PhD, EMT
Components of Energy Expenditure
Sport Performance and Metabolic Rate
Measurement of Energy Expenditure
Prediction of Energy Expenditure
Estimation of 24-hour and Physical Activity Energy Expenditure
Relevance and Applications for Metabolic Testing
Summary
Chapter 5: Aerobic Power
Jonathan Anning, PhD
Regression Equation Variables
Maximal Exercise Testing Methods
Submaximal Exercise Testing Methods
Regression Equation Calculations
Summary
Chapter 6: Lactate Threshold
Dave Morris, PhD
Energy Pathways and Lactate Metabolism
Sport Performance and Lactate Threshold
Performing a Lactate Threshold Test
Maximal Lactate Steady State
Using Lactate Threshold Data
Summary
Chapter 7: Muscular Strength
Gavin Moir, PhD
Definition of Muscular Strength
Factors Affecting Muscular Force Production
Sports Performance and Muscular Strength
Methods of Measurement
Field Tests for Muscular Strength
Predicting 1RM Values from Multiple Repetitions
Laboratory Tests for Maximal Muscular Strength
Isokinetic Strength Testing
Summary
Chapter 8: Muscular Endurance
Gavin Moir, PhD
Definition of Muscular Endurance
Field Tests for Muscular Endurance
Laboratory Tests for Muscular Endurance
Summary
Chapter 9: Power
Mark D. Peterson, PhD
Operationalizing Power
Mechanisms of Power Production and Expression
Types and Factors of Power
Sport Performance and Power
Tests for Power
Lower Body Tests
Upper Body Tests
Warm-Up and Postactivation Potentiation (PAP): A Special Consideration for Testing Power
Summary
Chapter 10: Speed and Agility
N. Travis Triplett, PhD
Speed
Agility
Sport Performance and Speed and Agility
Test Selection
Methods of Measurement
Summary
Chapter 11: Mobility
Sean P. Flanagan, PhD
Fundamental Concepts of Mobility
Sport Performance and Mobility
Mobility Testing
Range of Motion Tests
Interpretation of Results
Comparing Mobility Measurement Methods
Summary
Chapter 12: Balance and Stability
Sean P. Flanagan, PhD
Body Mechanics
Control Theory
Balance and Stability Tests
Sport Performance and Balance and Stability
Measuring Balance and Stability
Interpreting the Results
Founded in 1978, the National Strength and Conditioning Association (NSCA) is an international nonprofit educational association with members in more than 56 countries. Drawing on its vast network of members, the NSCA develops and presents the most advanced information regarding strength training and conditioning practices, injury prevention, and research findings.
Unlike any other organization, the NSCA brings together a diverse group of professionals from the sport science, athletic, allied health, and fitness industries. By working to find practical applications for new research findings in the strength and conditioning field, the association fosters the development of strength training and conditioning as a discipline and as a profession.
Todd A. Miller, PhD, is an associate professor of exercise science at the George Washington University School of Public Health and Health Services in Washington DC, where he is responsible for the development and oversight of the master's degree concentration in strength and conditioning. He has degrees in exercise physiology from Penn State and Texas A&M and currently studies the role of interactive video gaming as a means of increasing physical activity in children.
“This book takes an aggressive, holistic approach to the longstanding profession of strength and conditioning. The authors make a first-rate effort to move the profession of strength and conditioning forward into a new realm of expertise as professionals in the business of getting athletes to perform beyond their own expectations.”
-- Doody’s Book Review
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Effectively estimate 24-hour and physical activity energy expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry.
Estimation of 24-Hour and Physical Activity Energy Expenditure
It is very costly, and in most cases impractical, to measure 24-hour energy expenditure or to monitor physical activity energy expenditure through either direct or indirect calorimetry. These two methods of measurement are used only for research and clinical applications. Therefore, most professionals use energy expenditure prediction equations, movement analysis devices, or both, to estimate the energy cost of physical activity and the 24-hour energy expenditure for their clients. Tools used to monitor physical activity and estimate energy expenditure range from expensive and sophisticated machines, which are found only in health centers, to inexpensive gadgets and activity diaries, which can be found in almost any setting.
Activity Monitors
The most plausible tools for measuring either 24-hour energy expenditure or physical activity energy expenditure in the field are pedometers, accelerometers, and heart rate monitors. Pedometers are more suited for monitoring physical activity than 24-hour energy expenditure, whereas accelerometers and heart rate monitors are well suited for both.
Pedometers
Pedometers have been around for several decades. The pedometer itself measures the number of steps taken during the day. The summation of these steps is converted to a distance, and energy expenditure is estimated based on the distance traveled. Pedometer estimates for physical activity energy expenditure correlate moderately well with indirect calorimetry measures (Brown, Miller, and Eason 2006). However, only the total distance traveled is recorded on the pedometer, and there is no indication of the intensity of the physical activity. Therefore, pedometers are useful for gaining insight into 24-hour energy expenditure, but do not offer any reference to exercise intensity or activity patterns throughout the day. An advantage of pedometers is that they are relatively inexpensive; even children can learn how to use them.
Accelerometers
Accelerometers work on a principle that is different from that of pedometers. Accelerometers contain tiny force transducers that continuously measure the intensity, frequency, and duration of movement for extended periods of time. The forces measured by the accelerometer are summed and recorded as counts per time frame. There is no consensus about the accelerometer count thresholds for defining mild, moderate, and high exercise intensities. Nonetheless, accelerometers are valid and reliable for monitoring physical activity counts in both children and adults. Correlation coefficients between accelerometer counts and indirect calorimetry measures range from about 0.60 to 0.85, which represent fairly high correlations (Brown, Miller, and Eason 2006).
The advantage of accelerometers over pedometers is that accelerometers can measure the intensity of energy expenditure throughout the day, and this information can be downloaded to a computer. The computer then generates the data and pinpoints the fluctuations in energy expenditure at any time of day. The computer also uses regression equations to calculate the actual energy expenditure from recorded activity counts.
Heart Rate Monitors
Heart rate is strongly related to respiratory rate and energy expenditure across a wide range of values. Heart rate monitors are similar to accelerometers in that they can accumulate data from short or long bouts of activity throughout the day. Heart rate data can also be downloaded to a computer, and the magnitude of fluctuations in heart rate during the day can be pinpointed. Regression equations are used to convert heart rate measures to energy expenditure.
Activity Surveys and Diaries
Activity diaries necessitate that the participant (or an adult observer in the case of young children) make a record of every activity undertaken throughout the day. The person describes the nature of the activity and the time spent participating. This record includes activities that are sedentary as well as those that require physical exertion. Predetermined values for the energy expenditure of each activity noted in the diary are applied, and the energy expenditure is summed across time and throughout the day.
Activity surveys are similar to activity diaries, but rather than record the actual events at the time they occur (or shortly thereafter), recorders estimate the activity of an average day or an average week or month. In other words, people describe their usual routines over a period of many days, rather than recording actual events over a period of a few days. Calculations for energy expenditure are performed as with activity diaries to get the estimated energy expenditure.
The accuracy of physical activity surveys and diaries is variable; they range from being rather poor indicators of actual physical activity to being relatively good measures of physical activity. Activity surveys and diaries for children tend to be less accurate than those intended for adults. Nonetheless, physical activity surveys and diaries are commonly used to determine physical activity levels in both children and adults, because they are inexpensive, unobtrusive, and easily administered.
Many physical activity surveys have been designed for adults. Some of these have been intended for specific populations, or constructed specifically for independent research studies. The reliability and validity of these surveys is variable. The most popular of these surveys were collected and published by the American College of Sports Medicine (1997) several years ago.
One of the most popular physical activity surveys is the International Physical Activity Questionnaire (Craig et al. 2002; IPAQ 2011). The IPAQ comes in a long and short version, and in several languages, and can be downloaded (IPAQ 2011). Both versions ask respondents to record their health-related physical activity for the past seven days. Both versions can be either administered by a professional (in person), or self-administered. The long version consists of 27 questions that focus on job-related physical activity, transportation-related physical activity, housework, recreation and sport activity, and sedentary or sitting time. The short version of the form asks only seven questions about time spent in vigorous physical activity, moderate intensity activity, walking, and sitting.
A popular physical activity diary for older children and adolescents is the Previous Day Physical Activity Recall (PDPAR; Children's Physical Activity Research Group 2011). The PDPAR was designed to provide accurate data on the type, frequency, intensity, and duration of physical activities; these are then used to estimate physical activity energy expenditure (Weston, Petosa, and Pate 1997). The PDPAR is an activity diary that is segmented into seventeen 30-minute intervals. Participants are given a list of 35 numbered activities in which youth normally engage. They record the number of the activity in which they participated for any given 30-minute interval of the previous day. For the selected activity, they also record the intensity as being very light (slow breathing and little or no movement), light (normal breathing and movement), medium (increased breathing and moderate movement), and hard (hard breathing and quick movement). An estimated energy expenditure value is then calculated for each activity within the given time frame.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Methods of measurement for muscular strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can.
Methods of Measurement for Muscular Strength
Although many of the factors affecting the expression of muscular strength cannot be controlled by the fitness professional interested in assessing muscular strength, many can. Therefore, before selecting a specific test of muscular strength, the fitness professional must consider several issues including the specificity of the test, the warm-up protocol, and the timing and order of muscular strength tests.
Specificity of Muscular Strength
From the preceding discussion of the mechanical and physiological factors affecting muscular strength, it should be apparent that the expression of muscular strength is specific to the test employed. Using tests of muscular strength that are mechanically dissimilar to the performance of interest can compromise the external and predictive validity of the data gathered. For example, differences between training and testing exercises in terms of the type of muscle contraction used (Abernethy and Jürimäe 1996; Rutherford and Jones 1986), open- versus closed-kinetic chain movements (Augustsson et al. 1998; Carroll et al. 1998), and bilateral versus unilateral movements (Häkkinen et al. 1996; Häkkinen and Komi 1983) have been shown to influence the magnitude of the gains in muscular strength accrued following a period of resistance training. Therefore, fitness professionals should consider the movement characteristics of any strength test used; the movements should be similar to the performance of interest with respect to the following mechanical factors (Siff 2000; Stone, Stone, and Sands 2007):
Movement Patterns
- Complexity of movement. This involves such factors as single versus multijoint movements.
- Postural factors. The posture adopted in a given movement dictates the activation of the muscles responsible for force production.
- Range of motion and regions of accentuated force production. During typical movements, the range of motion at a joint will change as will the associated muscular forces and torques. Such information can be gathered from a biomechanical analysis of the movement.
- Muscle actions. This concerns the performance of concentric, eccentric, or isometric muscle contractions. As mentioned previously, such information is not always intuitive and may not be identifiable from observing the joint motion associated with the movement.
Force Magnitude (Peak and Mean Force)
Force magnitude refers to joint torques as well as ground reaction forces (GRF) during the movement. This information is garnered from biomechanical analyses.
Rate of Force Development (Peak and Mean Force)
Rate of force development refers to the rate at which a joint torque or the GRF is developed.
Acceleration and Velocity Parameters
Usually, in sporting and everyday movements, both velocity and acceleration characteristics change throughout the movement. Velocity is defined as the rate at which the position of a body changes per unit of time, whereas acceleration refers to the rate at which the velocity changes per unit of time. Given Newton's second law of motion (a = F / m), the greatest accelerations are observed when the net forces acting on the body are largest. However, the greatest velocities will not coincide with the largest accelerations and, therefore, the largest net forces (unless the person is moving in a dense fluid such as water).
Ballistic Versus Nonballistic Movements
Ballistic movements are those in which motion results from an initial impulse from a muscular contraction, followed by the relaxation of the muscle. The motion of the body continues as a result of the momentum that it possesses from the initial impulse (this is the impulse-momentum relationship). This is in contrast to nonballistic movements, in which muscular contraction is constant throughout the movement. These categories of movements involve different mechanisms of nervous control.
Consideration of these mechanical variables will increase the likelihood of selecting a valid test of the muscular strength. Researchers have raised the concern that the relationships among the dependent variables associated with strength tests (e.g., maximal external load lifted, maximal force generated) and performance variables are rarely actually assessed (Abernethy, Wilson, and Logan 1995; Murphy and Wilson 1997). These relationships are discussed in relation to each test covered in this chapter where appropriate.
The type of equipment used for muscular strength tests has significant implications. For example, some tests of muscular strength can be performed using either machine weights, in which the movement is constrained to follow a fixed path, or free weights, in which the movement is relatively unconstrained. However, a test performed with machine weights will not necessarily produce the same outcome as the same test performed with free weights. Cotterman, Darby, and Skelly (2005) reported that the values recorded for measures of maximal muscular strength were different during both the squat and bench press movements when the exercises were performed in a Smith machine compared to when they were performed with free weights. Testing muscular strength with different types of equipment introduces significant systematic bias into the data and therefore severely compromises the reliability of the measures as well as the external validity.
Warm-Up Considerations
A warm-up is often performed prior to exercise to optimize performance and reduce the risk of injury (Bishop 2003, a and b; Shellock and Prentice 1985). As stated previously, the force capabilities of a muscle can be affected by the completion of previous contractions, resulting in either a decrease in force (fatigue) or an increase in force (PAP). Indeed, both fatigue and PAP are proposed to exist at opposite ends of a continuum of skeletal muscle contraction (Rassier 2000). Therefore, exercises performed as part of an active warm-up could significantly alter the expression of muscular strength during the test.
An increase in the temperature of the working muscles has been reported following both passive (e.g., external heating) and active (e.g., engaging in specific exercises) warm-up activities (Bishop 2003, a and b). However, the effects of increased temperature on measures of maximal muscular strength are unclear with increases in maximal isometric torque reported by some authors (Bergh and Ekblom 1979), whereas others have reported no change (de Ruiter et al. 1999).
Static stretches are often included in the warm-up routines of athletes. Researchers have reported a reduction in force during maximal voluntary contractions following an acute bout of static stretches (Behm, Button, and Butt 2001; Kokkonen, Nelson, and Cornwell 1998), leading some to propose that static stretches be excluded from warm-up routines prior to strength and power performances (Young and Behm 2002). However, Rubini, Costa, and Gomes (2007) recently noted methodological issues with many of the static stretching studies, concluding that an interference with muscular strength is usually observed following a stretching protocol in which many exercises are held for relatively long durations, which runs counter to common practice.Therefore, including static stretches in a warm-up routine prior to muscular strength testing may be permissible, as long as the total stretch duration is not excessive (four sets of exercises for each muscle group with 10-30 seconds stretch duration is recommended) and that the exercises are performed consistently during subsequent testing sessions.
Clearly, the warm-up performed prior to a strength test can have a significant influence on the expression of muscular strength, and so the examiner should give the warm-up due consideration. However, the most important factor associated with the warm-up would appear to be the consistency of the exercises incorporated; any alteration in the exercises performed will compromise the validity and reliability of the test. Jeffreys (2008) outlined the following warm-up protocols:
- General warm-up. Five to 10 minutes of low-intensity activity aimed at increasing heart rate, blood flow, deep muscle temperature, and respiration rate.
- Specific warm-up. Eight to 12 minutes of performing dynamic stretches incorporating movements that work through the range of motion required in the subsequent performance. This period is followed by gradually increasing the intensity of the movement-specific dynamic exercises.
Timing and Order of Tests
Researchers have reported that the expression of strength under both isometric and isokinetic conditions is affected by the time of day the tests are taken, with greater strength values being recorded in the early evening (Guette, Gondin, and Martin 2005; Nicolas et al. 2005). Although the mechanisms behind this diurnal effect are unclear, the implication is that examiners need to consider the time of day when administering strength tests and to ensure consistency when administering the test during future sessions.
A test of muscular strength may be one of a number of tests performed on a person. In this case, the fitness professional needs to consider where to place the muscular strength test in the battery. This consideration is important given the effect that contractile history can have on the expression of muscular strength. Harman (2008) proposed the following order for tests in a battery based on energy system requirements and the skill or coordination demands of the tests:
Nonfatiguing tests (anthropometric measurements)
Agility tests
Maximum power and strength tests
Sprint tests
Muscular endurance tests
Fatiguing anaerobic tests
Aerobic capacity tests
Following this order should maximize the reliability of each test.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Examine upper body tests for power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities.
Upper Body Tests for Power
The majority of tests and training protocols emphasize lower extremity muscular power. However, upper extremity power production and performance are also exceedingly important for most sports and activities. Two primary tests to examine maximal upper extremity anaerobic capacity and power are the Upper Body Wingate Anaerobic Test and the Medicine Ball Put. Each of these tests has been validated numerous times and has proven reliable across multiple populations.
Upper Body Wingate Anaerobic Test
Similar to the traditional WAnT for the lower body, the Upper Body Wingate Anaerobic Test is generally performed in a laboratory setting and has the advantage of providing several outcomes related to upper body anaerobic capacity. This test occurs with a 30-second time course using a modified cycle ergometer with an arm crank. The calculation of peak power is typically acquired within the first three to five seconds of work, and is expressed in total watts (W), or relative to body mass (W/kg). Further, using the entire 30 seconds of arm cranking, anaerobic capacity (AC) may be calculated as the total external work performed, and is expressed in kilojoules (kJ). Lastly, anaerobic fatigue is often reported, which allows for the calculation of the percentage of power output reduction throughout the test (i.e., fatigue index).
Equipment
- Mechanically braked cycle ergometer with additional adjustment for an arm crank (i.e., a cycle ergometer with handles where the pedals normally are)
- Table for mounting the ergometer for testing. This should be higher than 70 centimeters (27.6 in.) and have room for legs underneath.
- Additional weight (80 to 100 kg, or 176 to 220 lb) to load the ergometer to prevent movement during the test
- Optical sensor to detect and count reflective markers on the flywheel
- Computer and interface with appropriate software (e.g., Sports Medicine Industries, Inc.)
Procedure
1. The subject should be seated comfortably in a chair placed behind the cycle ergometer so that the feet are flat on the floor. This allows the subject to pedal with no restrictions.
2. Warm-up: After initial familiarization with and individual adjustment of the upper body ergometer, the subject performs three to five minutes of light arm cranking, with no load or a load that is less than 20% of the load used for the actual test. At the end of each minute of the warm-up, the subject should perform approximately five seconds of maximal arm cranking.
3. Following the specific warm-up, the subject should participate in light dynamic stretching of the entire shoulder joint, pectoral musculature, and muscles of the biceps, triceps, and forearms. This time may also be used to further explain testing instructions.
4. The test is initiated with the subject cranking at maximal cadence against no load. A verbal command of “Go” provides the auditory cue to begin arm cranking. Once the subject is at maximal cadence (usually in the first one to three seconds), apply the external load for the 30-second all-out test. Load = 0.050 kilogram per kilogram of body mass (Monark cycle ergometer) (Nindl et al. 1995).
5. Following the application of the appropriate resistance, the 30-second test is started, and data collection commences. The subject must remain seated throughout the entire 30 seconds.
6. Flywheel revolutions per minute (rpm) are counted (preferably by photocell and computer interface), and peak power is calculated based on maximal rpm (usually over the first five seconds of work) and angular distance. Each revolution is equal to 1.615 meters.
7. The test is terminated after 30 seconds of all-out work. Following the test, a two- to five-minute cool-down period is recommended.
Outcome Measures
See the section Wingate Anaerobic Test. Table 9.9 provides typical values for peak mean power in males and females for the Upper Body Wingate Anaerobic Test.
Medicine Ball Put
The field test most frequently used to measure power of the upper body is the seated medicine ball put (Clemons, Campbell, and Jeansonne 2010).The widespread popularity of this test is due not only to the ease of administration, but also to the direct specificity of this movement to a functional task such as the chest pass in basketball, or even the rapid punching of combat athletes. Moreover, because this exercise is commonly used in training, test data may easily be extrapolated to training prescription.
Equipment
- 45° incline bench
- High-durability medicine ball: 6 kilograms (13.2 lb) for females, 9 kilograms (19.8 lb) for males (Clemons, Campbell, and Jeansonne 2010)
- Gymnastics chalk (i.e., carbonate of magnesium)
- Measuring tape
- Room or gymnasium with at least 8 meters (26 feet) of clearance
Procedure
1. The measuring tape is placed on the floor with the end positioned under the front frame of the bench, to anchor it.
2. The tip of the tape should be positioned so it is aligned with the outside of the medicine ball while it rests on the subject's chest (i.e., in the ready position, prior to putting the ball) (Clemons, Campbell, and Jeansonne 2010; see figure 9.6).
3. The tape should be extended outward from the bench for at least 8 meters (26 feet), and secured to the floor.
4. Warm-up: After initial familiarization with the bench orientation and putting procedure, the subject performs five minutes of moderate-intensity aerobic exercise, followed by several dynamic range of motion exercises for the shoulder and elbow joint (e.g., modified or regular push-ups or hand walk-outs). The subject is then allowed several submaximal trials with the appropriate medicine ball.
5. For the test, the subject should be seated comfortably on the incline bench with feet flat on the floor and the medicine ball against the chest.
6. The subject grasps the medicine ball with both hands, one on each side.
7. Without any additional bodily movement (e.g., trunk or neck flexion, arm countermovement), the subject attempts to propel (i.e., “put”) the medicine ball at an optimal trajectory of 45°, for maximal horizontal distance.
8. Every attempt should be made to propel the ball in a straight line, to yield valid data.
9. Three to five attempts are permitted, with a minimum of two minutes of rest between attempts.
Outcome Measures
Each test attempt should be measured by the closest chalk mark (i.e., in the direction of the bench) and recorded to the nearest centimeter or inch.
Modifications
This test has been used extensively with various loading parameters and across populations. Further, many studies have reported the use of upright benches (i.e., seated upright at 90°) instead of 45° incline benches. To maintain test quality, examiners should use the same protocol each time a given subject is tested.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Measure balance and stability
Measuring Balance and Stability
Fitness professionals should first establish the purpose of the test, pick a category that would fulfill that purpose, and then select a test based on the level of precision required and the resources available. Three tests, the balance error scoring system (BESS), the star excursion balance test (SEBT), and the modified Bass test, were selected for detailed discussion here because they represent different categories (postural steadiness, reach, and postural stability) and require minimal specialized equipment. Additionally, the BESS and SEBT have excellent reliability and a large body of literature supporting them. Interested readers should consult the original literature cited in the reference section for detailed procedures on conducting the other tests. Table 12.1 compares balance and stability evaluations.
Balance Error Scoring System (BESS)
Equipment
A foam balance pad. The foam pad is one piece of medium-density foam (45 cm2× 13 cm thick, density 60 kg/m3, load deflection 80-90).
Procedure
The six positions of the balance error scoring system test are depicted in figure 12.3. Three stances (double-leg support, single-leg support, and tandem) are held for 20 seconds on two surfaces (firm floor and foam pad) for six permutations (Riemann, Guskiewicz, and Shields 1999). During the tandem stance, the dominant foot is in front of the nondominant foot. During the single-leg stance, the subject stands on the nondominant foot. During the test, the eyes are closed and the hands are held on the hips (iliac crests).
Subjects are told to keep as steady as possible, and if they lose their balance, they are to try to regain the initial position as quickly as possible. Subjects are assessed one point for the following errors: lifting the hands off the iliac crests; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel (Riemann, Guskiewicz, and Shields 1999). A trial is considered incomplete if the subject cannot hold the position without error for at least five seconds. The maximal number of errors per condition is 10. An incomplete condition is given the maximal number of points (10). The numbers of errors for all six conditions are summed into a single score.
Star Excursion Balance Test (SEBT)

Equipment
Athletic or masking tape
Procedure
The SEBT requires the floor to be marked with a star pattern in eight directions, 45° apart from each other: anterior, posterior, medial, lateral, posterolateral, posteromedial, anterolateral, and anteromedial (see figure 12.4). One foot is placed in the middle of the star pattern. The subject is instructed to reach as far as possible, sequentially (either clockwise or counter clockwise), in all eight directions.
The directions are not labeled consistently in the literature. For example, when balancing on the left leg and reaching to the right with the right leg, some authors call this direction medial (Gribble and Hertel 2003; Hertel et al. 2006), whereas others call it lateral (Bressel et al. 2007). This text adopts the convention that, when standing on the left leg, reaching to the right of the left leg is in the medial direction, whereas reaching to the left (and behind the stance leg) is in the lateral direction (see figure 12.4).
The subject makes a light tap on the floor, and then returns the leg to the center of the star. The distance from the center of the star to the tap is measured. The trial is nullified and has to be repeated if the subject commits any of the following errors: makes a heavy touch, rests the foot on the ground, loses balance, or cannot return to the starting position under control (Gribble 2003). The starting direction and support leg are chosen randomly. Three trials are performed and then averaged.
Because of the significant correlation between SEBT and leg length (.02 ≤ r2≤ .23) in a majority of the directions, excursion values should be normalized to leg length, measured from the ASIS to the medial malleolus (Gribble and Hertel 2003). Additionally, Hertel and colleagues (2006) suggested that testing in eight directions is redundant, and that testing only the posteromedial direction is sufficient for most situations. To decrease the effect of learning, Kinzey and Armstrong (1998) suggested that subjects be given at least six practice trials before being tested, although other authors suggested reducing the number of practice trials to four (Robinson and Gribble 2008).
Modified Bass Test

Equipment
Athletic or masking tape
Procedure
This multiple hop test requires that 1-inch (2.5 cm) tape squares be laid out in a course as shown in figure 12.5 (Riemann, Caggiano, and Lephart 1999). The subject is required to jump from square to square, in numbered sequence, using only one leg. The hands should remain on the hips. On landing, the subject remains looking facing straight ahead, without moving the support leg, for five seconds before jumping to the next square.
There are two types of errors: landing errors and balance errors. A landing error occurs if the subject's foot does not cover the tape, if the foot is not facing forward, if the subject stumbles on landing, or if the subject takes the hands off the hips. A balance error occurs if the subject takes the hands off the hips or if the nontesting leg touches down, touches the opposite leg, or moves into excessive flexion, extension, or abduction. The subjects may look at the next square before jumping to it.
The examiner should count aloud the five seconds the subject is to maintain the position before moving to the next square. At the conclusion of the test, 10 points are given for each five-second period in which there was a landing error and 3 points for each period in which there was a balance error. The sum of the two is the total score. At least two practice sessions should be given before testing for score.
Interpreting the Results
When interpreting the results of balance or stability tests,values can be compared to normative data, the other leg (if performed on a single leg), or the same person over time. Normative data are presented for the BESS, SEBT, and modified Bass in tables 12.2 through 12.4, respectively. Currently, no data exist to suggest either a cutoff score for these tests or, in the case of the SEBT or modified Bass test, a bilateral difference that would be a cause for concern. These are areas for future investigations. Balance scores tend to be better in the morning than in the afternoon or evening (Gribble, Tucker, and White 2007), suggesting that if multiple tests are to be compared over time, the time of day needs to be standardized.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.
Using lactate threshold data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program.
Using Lactate Threshold Data
Information provided by a lactate threshold test has a number of purposes. By understanding the role that lactate plays in exercise metabolism, the exercise physiologist can use the information from lactate threshold tests to predict proper racing and training paces, and assess the fitness of a subject or the efficacy of the training program. Although lactate production does not contribute to acidosis and lactate itself does not appear to cause fatigue, blood lactate accumulation does indicate that the body is relying on substantial contributions from anaerobic glycolysis to meet exercising energy requirements. Knowing the exercise intensity at which this occurs is valuable for two reasons: When glucose and glycogen are metabolized to lactate, only two or three ATP moleculesare generated per molecule of carbohydrate consumed compared to the 36 to 39 ATP moleculesthat are generated when pyruvate is produced and consumed through oxidative phosphorylation. Thus, the advent of lactate threshold signals that the body is consuming glucose and glycogen at an increased rate in respect to ATP production, which, ultimately, can lead to premature carbohydrate depletion and exhaustion. Therefore, athletes who partake in events that challenge their glycogen storage capacity should take into consideration the need to preserve carbohydrate stores when planning their pacing strategies.
Increases in blood lactate concentrations also indicate that the subject's ATP consumption rate is beginning to exceed the ability to provide ATP through the oxidative pathway. The increase in blood lactate levels seen at this transitional intensity indicates that the body has to rely on glycolysis to provide adequate ATP supplies for the exercising muscle. Though lactate production does not result in acidosis and has a questionable role in causing fatigue, the accumulation of lactate in the blood indicates that maximal sustainable rates of exercise and ATP production are close at hand (Morris and Shafer 2010).
The relationship between lactate threshold and the rate of consumption of carbohydrate stores, and correlations between lactate threshold and maximal sustainable work rate, make lactate threshold a good predictor of endurance exercise performance. Previous studies (Foxdal et al. 1994; Tanaka 1990) have demonstrated close agreements between running paces at lactate threshold and average paces during competitive running events in distances ranging from 10,000 meters to the marathon. In studies using cycling ergometry, power outputs that elicited lactate threshold were similar to average power outputs during time trials ranging from 60 to 90 minutes (Bentley et al. 2001; Bishop, Jenkins, and Mackinnon 1998). However, in time trials ranging from 25 to 35 minutes, subjects typically maintain significantly higher power outputs than those that elicited lactate threshold (Bentley et al. 2001; Kenefick et al. 2002). Despite these discrepancies, correlations between power outputs at lactate threshold and average power outputs during the shorter time trials remained remarkably high, suggesting that performance in these events can be predicted from lactate threshold data with reasonable accuracy.
As in many physiological and anatomical systems, the mechanisms that influence lactate threshold are responsive to exercise training. Properly designed training programs can increase the capacity of the oxidative pathway by increasing oxygen delivery to the working muscle (Schmidt et al. 1988), mitochondrial numbers (Holloszy and Coyle 1984), and oxidative enzyme levels (Henriksson and Reitman 1976). These improvements in oxidative capacity increase the muscle's ability to produce ATP, consume pyruvate, and regenerate NAD resulting in a reduced reliance on lactate production and an increase in work rates that are required to elicit lactate threshold.
Unlike maximal oxygen consumption, which can be significantly influenced by genetic factors (Bouchard et al. 1986), the exhibition of lactate threshold when expressed as a percentage of maximal oxygen consumption is primarily influenced by the level of conditioning (Henritze et al. 1985). This sensitivity to exercise training makes lactate threshold useful for assessing aerobic fitness and the efficacy of training programs. Well-trained endurance athletes tend to exhibit lactate threshold when exercising at 80% or more of their maximal oxygen consumption, whereas untrained people experience lactate threshold at substantially lower intensities (Joyner and Coyle 2008). Continued training at or above the work rate that elicits lactate threshold also results in increases in the power outputs that cause increased rates of lactate production and accumulation (Henritze et al. 1985). Therefore, the efficacy of a training program can be assessed by measuring lactate threshold prior to, and following, program implementation. A rightward shift, as seen in figure 6.10, suggests that the training program has been successful in increasing the work rate that elicits lactate threshold and maximal sustainable work rates.
The ability of lactate threshold to respond to training and predict competitive performance also makes it useful in prescribing proper training intensities. Scientific evidence supports the overload principle of training (Weltman et al. 1992), which suggests that the most effective way to improve physiological capacity is to train at an intensity that exceeds current ability. Thus, effective training strategies involve assessing athletes' current performance capacities and using work intervals that exceed their current maximal sustainable work rates. Undoubtedly, the most accurate way of measuring an athlete's performance capacity in a particular event is to measure performance during that event. Unfortunately, lengthy endurance events such as the marathon are physically taxing, which makes performing them simply to test performance capacity impractical. However, the relatively short and low-stress nature of a lactate threshold test makes it ideal for frequently assessing an athlete's ability.
Read more from NSCA's Guide to Tests and Assessments by NSCA -National Strength & Conditioning Association and Todd Miller.