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Essentials of Strength Training and Conditioning
Edited by NSCA -National Strength & Conditioning Association
752 Pages
The scope and content of Essentials of Strength Training and Conditioning, Fourth Edition With HKPropel Access, have been updated to convey the knowledge, skills, and abilities required of a strength and conditioning professional and to address the latest information found on the Certified Strength and Conditioning Specialist (CSCS) exam. The evidence-based approach and unbeatable accuracy of the text make it the primary resource to rely on for CSCS exam preparation.
The text is organized to lead readers from theory to program design and practical strategies for administration and management of strength and conditioning facilities. The fourth edition contains the most current research and applications and several new features:
- Online videos featuring 21 resistance training exercises demonstrate proper exercise form for classroom and practical use.
- Updated research—specifically in the areas of high-intensity interval training, overtraining, agility and change of direction, nutrition for health and performance, and periodization—helps readers better understand these popular trends in the industry.
- A new chapter with instructions and photos presents techniques for exercises using alternative modes and nontraditional implements.
- Ten additional tests, including those for maximum strength, power, and aerobic capacity, along with new flexibility exercises, resistance training exercises, plyometric exercises, and speed and agility drills help professionals design programs that reflect current guidelines.
Key points, chapter objectives, and learning aids including key terms and self-study questions provide a structure to help students and professionals conceptualize the information and reinforce fundamental facts. Application sidebars provide practical application of scientific concepts that can be used by strength and conditioning specialists in real-world settings, making the information immediately relatable and usable. Online learning tools delivered through HKPropel provide students with 11 downloadable lab activities for practice and retention of information. Further, both students and professionals will benefit from the online videos of 21 foundational exercises that provide visual instruction and reinforce proper technique.
Essentials of Strength Training and Conditioning, Fourth Edition, provides the most comprehensive information on organization and administration of facilities, testing and evaluation, exercise techniques, training adaptations, program design, and structure and function of body systems. Its scope, precision, and dependability make it the essential preparation text for the CSCS exam as well as a definitive reference for strength and conditioning professionals to consult in their everyday practice.
Note: A code for accessing HKPropel is included with all new print books.
Chapter 1. Structure and Function of Body Systems
N. Travis Triplett, PhD
Musculoskeletal System
Neuromuscular System
Cardiovascular System
Respiratory System
Conclusion
Learning Aids
Chapter 2. Biomechanics of Resistance Exercise
Jeffrey M. McBride, PhD
Skeletal Musculature
Anatomical Planes and Major Body Movements
Human Strength and Power
Sources of Resistance to Muscle Contraction
Joint Biomechanics: Concerns in Resistance Training
Conclusion
Learning Aids
Chapter 3. Bioenergetics of Exercise and Training
Trent J. Herda, PhD, and Joel T. Cramer, PhD
Essential Terminology
Biological Energy Systems
Substrate Depletion and Repletion
Bioenergetic Limiting Factors in Exercise Performance
Oxygen Uptake and the Aerobic and Anaerobic Contributions to Exercise
Metabolic Specificity of Training
Conclusion
Learning Aids
Chapter 4. Endocrine Responses to Resistance Exercise
William J. Kraemer, PhD, Jakob L. Vingren, PhD, and Barry A. Spiering, PhD
Synthesis, Storage, and Secretion of Hormones
Muscle as the Target for Hormone Interactions
Role of Receptors in Mediating Hormonal Changes
Categories of Hormones
Heavy Resistance Exercise and Hormonal Increases
Mechanisms of Hormonal Interactions
Hormonal Changes in Peripheral Blood
Adaptations in the Endocrine System
Primary Anabolic Hormones
Adrenal Hormones
Other Hormonal Considerations
Conclusion
Learning Aids
Chapter 5. Adaptations to Anaerobic Training Programs
Duncan French, PhD
Neural Adaptations
Muscular Adaptations
Connective Tissue Adaptations
Endocrine Responses and Adaptations to Anaerobic Training
Cardiovascular and Respiratory Responses to Anaerobic Exercise
Compatibility of Aerobic and Anaerobic Modes of Training
Overtraining
Detraining
Conclusion
Learning Aids
Chapter 6. Adaptations to Aerobic Endurance Training Programs
Ann Swank, PhD, and Carwyn Sharp, PhD
Acute Responses to Aerobic Exercise
Chronic Adaptations to Aerobic Exercise
Adaptations to Aerobic Endurance Training
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training
Overtraining: Definition, Prevalence, Diagnosis, and Potential Markers
Conclusion
Learning Aids
Chapter 7. Age- and Sex-Related Differences and Their Implications for Resistance Exercise
Rhodri S. Lloyd, PhD, and Avery D. Faigenbaum, EdD
Children
Female Athletes
Older Adults
Conclusion
Learning Aids
Chapter 8. Psychology of Athletic Preparation and Performance
Traci A. Statler, PhD, and Andrea M. DuBois, MS
Role of Sport Psychology
Ideal Performance State
Energy Management: Arousal, Anxiety and Stress
Influence of Arousal and Anxiety on Performance
Motivation
Attention and Focus
Psychological Techniques for Improved Performance
Enhancing Motor Skill Acquisition and Learning
Conclusion
Learning Aids
Chapter 9. Basic Nutrition Factors in Health
Marie Spano, MS, RD
Role of Sport Nutrition Professionals
Standard Nutrition Guidelines
Macronutrients
Vitamins
Minerals
Fluid and Electrolytes
Conclusion
Learning Aids
Chapter 10. Nutrition Strategies for Maximizing Performance
Marie Spano, MS, RD
Precompetition, During-Event, and Postcompetition Nutrition
Nutrition Strategies for Altering Body Composition
Feeding and Eating Disorders
Conclusion
Learning Aids
Chapter 11. Performance-Enhancing Substances and Methods
Bill Campbell, PhD
Types of Performance-Enhancing Substances
Hormones
Dietary Supplements
Conclusion
Learning Aids
Chapter 12. Principles of Test Selection and Administration
Michael McGuigan, PhD
Reasons for Testing
Testing Terminology
Evaluation of Test Quality
Test Selection
Test Administration
Conclusion
Learning Aids
Chapter 13. Administration, Scoring, and Interpretation of Selected Tests
Michael McGuigan, PhD
Measuring Parameters of Athletic Performance
Selected Test Protocols and Scoring Data
Statistical Evaluation of Test Data
Conclusion
Learning Aids
Chapter 14. Warm-Up and Flexibility Training
Ian Jeffreys, PhD
Warm-Up
Flexibility
Types of Stretching
Conclusion
Static Stretching Techniques
Dynamic Stretching Techniques
Learning Aids
Chapter 15. Exercise Technique for Free-Weight and Machine Training Technique
Scott Caulfield, BS
Fundamentals of Exercise Technique
Spotting Free-Weight Exercises
Conclusion
Resistance Training Exercises
Learning Aids
Chapter 16. Exercise Technique for Alternative Modes and Nontraditional Implement Training
G. Gregory Haff, PhD, Doug Berninger, MEd, and Scott Caulfield, BS
General Guidelines
Body-Weight Training Methods
Core Stability and Balance Training Methods
Variable-Resistance Training Methods
Nontraditional Implement Training Methods
Unilateral Training
Conclusion
Alternative Modes and Nontraditional Exercises
Learning Aids
Chapter 17. Program Design for Resistance Training
Jeremy M. Sheppard, PhD, and N. Travis Triplett, PhD
Principles of Anaerobic Exercise Prescription
Step 1: Needs Analysis
Step 2: Exercise Selection
Step 3: Training Frequency
Step 4: Exercise Order
Step 5: Training Load and Repetitions
Step 6: Volume
Step 7: Rest Periods
Conclusion
Learning Aids
Chapter 18. Program Design and Technique for Plyometric Training
David H. Potach, PT, and Donald A. Chu, PhD, PT
Plyometric Mechanics and Physiology
Design of Plyometric Training Programs
Age Considerations
Plyometrics and Other Forms of Exercise
Safety Considerations
Conclusion
Plyometric Drills
Learning Aids
Chapter 19. Program Design and Technique for Speed and Agility Training
Brad H. DeWeese, EdD, and Sophia Nimphius, PhD
Speed and Agility Mechanics
Neurophysiological Basis for Speed
Running Speed
Agility Performance and Change-of-Direction Ability
Methods of Developing Speed
Methods of Developing Agility
Program Design
Speed Development Strategies
Agility Development Strategies
Conclusion
Speed and Agility Drills
Learning Aids
Chapter 20. Program Design and Technique for Aerobic Endurance Training
Benjamin H. Reuter, PhD, and J. Jay Dawes, PhD
Factors Related to Aerobic Endurance Performance
Designing an Aerobic Endurance Program
Types of Aerobic Endurance Training Programs
Application of Program Design to Training Seasons
Special Issues Related to Aerobic Endurance Training
Conclusion
Aerobic Endurance Training Exercises
Learning Aids
Chapter 21. Periodization
G. Gregory Haff, PhD
Central Concepts Related to Periodization
Periodization Hierarchy
Periodization Periods
Applying Sport Seasons to the Periodization Periods
Undulating Versus Linear Periodization Models
Example of an Annual Training Plan
Conclusion
Learning Aids
Chapter 22. Rehabilitation and Reconditioning
David H. Potach, PT, and Terry L. Grindstaff, DPT
Types of Injury
Tissue Healing
Rehabilitation and Reconditioning Strategies
Program Design
Reducing Risk of Injury and Reinjury
Conclusion
Learning Aids
Chapter 23. Facility Design, Layout, and Organization
Andrea Hudy, MA
General Aspects of New Facility Design
Existing Strength and Conditioning Facilities
Assessing Athletic Program Needs
Designing the Strength and Conditioning Facility
Arranging Equipment in the Strength and Conditioning Facility
Maintaining and Cleaning Surfaces and Equipment
Conclusion
Learning Aids
Chapter 24. Facility Policies, Procedures, and Legal Issues
Traci Statler, PhD, and Victor Brown, MS
Mission Statement and Program Goals
Legal and Ethical Issues
Staff Policies and Activities
Facility Administration
Emergency Planning and Response
Conclusion
The National Strength and Conditioning Association (NSCA) is the world’s leading organization in the field of sport conditioning. Drawing on the resources and expertise of the most recognized professionals in strength training and conditioning, sport science, performance research, education, and sports medicine, the NSCA is the world’s trusted source of knowledge and training guidelines for coaches and athletes. The NSCA provides the crucial link between the lab and the field.
G. Gregory Haff, PhD, CSCS,*D, FNSCA, is the course coordinator for the postgraduate degree in strength and conditioning at Edith Cowan University in Joondalup, Australia. He is the president of the National Strength and Conditioning Association (NSCA) and a senior associate editor for the Journal of Strength and Conditioning Research. Dr. Haff was the United Kingdom Strength and Conditioning Association (UKSCA) Strength and Conditioning Coach of the Year for Research and Education and the 2011 NSCA William J. Kraemer Outstanding Sport Scientist award winner. He is a certified strength and conditioning specialist with distinction, a UKSCA-accredited strength and conditioning coach, and an accredited Australian Strength and Conditioning Association level 2 strength and conditioning coach. Additionally, he is a national-level weightlifting coach in the United States and Australia. He serves as a consultant for numerous sporting bodies, including teams in the Australian Football League, Australian Rugby Union, Australian Basketball Association, and National Football League.
N. Travis Triplett, PhD, CSCS,*D, FNSCA, is a professor and chairperson of the department of health and exercise science at Appalachian State University in Boone, North Carolina. She has served as the secretary-treasurer of the board of directors for the National Strength and Conditioning Association (NSCA) and was the 2010 NSCA William J. Kraemer Outstanding Sport Scientist award winner. She has served on two panels for NASA, one for developing resistance exercise countermeasures to microgravity environments for the International Space Station, and was a sports physiology research assistant at the U.S. Olympic Training Center in Colorado Springs, Colorado. Dr. Triplett is currently a senior associate editor for the Journal of Strength and Conditioning Research and is a certified strength and conditioning specialist with distinction as well as a USA Weightlifting club coach.
“This is the most comprehensive reference available for exercise professionals in the area of strength and conditioning. The depth of information is unmatched, and the level of current research dissemination is excellent.”
©Doody’s Review Service, 2016, Kimberly Friedman, MS, The Ohio State University
Instructor guide. Includes additional resources to aid in lecture preparation, including sample discussion questions, key terms with definitions, and chapter objectives and outlines.
Instructor video. Includes the 21 resistance training videos that appear in the web resource, plus 40 videos that demonstrate various plyometric exercises and alternative modes that bring practical content to the classroom.
Test package. Includes 240 multiple-choice questions.
Presentation package plus image bank. Includes more than 1,300 PowerPoint slides to augment classroom discussion and lectures. Over 600 figures, tables, and images from the book are organized by chapter and can be used by instructors in handouts and classroom activities to reinforce key concepts.
The presentation package plus image bank is also available for purchase • ISBN 978-1-4925-0163-3
Student web resource with online video. Includes lab activities in fillable form and 21 video clips of resistance training exercises. These videos plus 40 more are also found in the instructor video library.
The web resource with online video is also available for purchase • ISBN 978-1-4925-0166-4
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
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Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
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Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
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Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Manage overload and recovery to prevent overtraining
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140).
The goal of training is to provide incremental overload on the body so that physiological adaptations can subsequently contribute to improved performance. Successful training must not only involve overload, but must also avoid the combination of excessive overload with inadequate recovery (140). When training frequency, volume, or intensity (or some combination of these) is excessive without sufficient rest, recovery, and nutrient intake, conditions of extreme fatigue, illness, or injury (or more than one of these) can occur (110, 124, 185). This accumulation of training stress can result in long-term decrements in performance with or without associated physiological and psychological signs and symptoms of maladaptation, and is referred to as overtraining. Depending on the extent to which an athlete is overtrained, restoration of performance can take several weeks or months (81, 140).
When an athlete undertakes excessive training that leads to short-term decrements in performance, this temporary response has been termed overreaching or functional overreaching (FOR) (58, 163). Recovery from this condition is normally achieved within a few days or weeks of rest; consequently, overreaching can be prescribed as a planned phase in many training programs. The rationale is to overwork (to suppress performance and build up tolerance) and then taper in order to allow for a "supercompensation" in performance. In fact, it has been shown that short-term overreaching followed by an appropriate tapering period can result in beneficial strength and power gains (163). When mismanaged, however, it can lead to detrimental effects (144).
When the intensification of a training stimulus continues without adequate recovery and regeneration, an athlete can evolve into a state of extreme overreaching, or nonfunctional overreaching (NFOR). This NFOR leads to stagnation and a decrease in performance that will continue for several weeks or months. When an athlete does not fully respect the balance between training and recovery, the first signs and symptoms of prolonged training distress are decreased performance, increased fatigue, decreased vigor, and hormonal disturbances. When those occur, it becomes difficult to differentiate between NFOR and what has been termed overtraining syndrome (OTS). Central to the definition of OTS is a "prolonged maladaptation" not only of the athlete, but also of several biological, neurochemical, and hormonal regulation mechanisms. Many alternative terms have been suggested for OTS, including burnout, chronic overwork, staleness, unexplained underperformance syndrome, and overfatigue (21, 23). Figure 5.6 illustrates the progression that composes the overtraining continuum.

The overtraining continuum.
Overtraining syndrome can last as long as six months or beyond; and in the worst-case scenario, OTS can ruin an athletic career. Two distinct types of OTS have been proposed: sympathetic and parasympathetic. The sympathetic overtraining syndrome includes increased sympathetic activity at rest, whereas the parasympathetic overtraining syndrome involves increased parasympathetic activity at rest and with exercise (140). The sympathetic syndrome is thought to develop before the parasympathetic syndrome and predominates in younger athletes who train for speed or power (58). Eventually all states of overtraining culminate in the parasympathetic syndrome and the chronic suppression of most physiological systems throughout the body (140). Because rebounds are possible, it is difficult to determine exactly when overtraining becomes chronic. In addition, some athletes respond positively to overreaching strategies (163) whereas for others, overreaching can be the catalyst for OTS.
A predominant feature of OTS is the inability to sustain high-intensity exercise when training load is maintained or increased (141). In many cases OTS is a consequence of prolonged NFOR, which in itself can result from mistakes in the prescription of training load and a mismanagement of the acute training variables (e.g., intensity, volume, rest). A common mistake in overtrained athletes is a rate of progressive overload that is too high. That is, increasing either the volume or intensity (or both) too rapidly over a period of several weeks or months with insufficient recovery can result in greater structural damage over time and, potentially, overtraining. A theoretical overview of anaerobic overtraining is presented in table 5.3.
For the purpose of investigating overtraining, deliberately causing OTS is not easy in a laboratory setting. What is more, while the symptoms of OTS are generally thought of as more severe than those of NFOR, there is no scientific evidence to confirm or refute this suggestion (140), making it hard to confirm that OTS has occurred. Instead, longitudinal monitoring of athletes has been the most practical way of documenting the physiological responses and performance effects of overtraining. The majority of this research has been conducted in endurance-type sports, where it is perhaps more prevalent. However, a survey of overtrained athletes showed that 77% were also involved in sports requiring high levels of strength, speed, or coordination (58). The symptoms of overtraining found in anaerobic activities (sympathetic) were also different from those in aerobic - endurance activities (parasympathetic) (23, 58).
Sympathetic-type overtraining is a little more difficult to characterize than parasympathetic overtraining. It can be speculated that increased neural activity consequent to excessive motor unit activation may bring about this type of overtraining; however, there are many other factors that could potentially contribute. Adopting a short-term NFOR model (eight sets of machine squats with a 95% 1RM load for six consecutive days), Fry and colleagues (59) examined intensity-specific responses and reported nonspecific performance decreases in isokinetic torque production, longer sprint times, and longer agility times. They did, however, find that 1RM strength was preserved. In a subsequent study by Fry and associates (62), subjects performed 10 sets of 1RM over seven days with a day's rest. This resulted in a significant decrease (>9.9 pounds [4.5 kg]) in the 1RM in 73% of the subjects. Interestingly, some subjects made progress and did not reach a NFOR state. This demonstrates that the time course for the onset of overreaching or overtraining symptoms is greatly dependent on individual responses, training status, and genetic endowment.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Optimize HIIT training adaptations for athletes and clients
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations.
High-intensity interval training (HIIT) involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. High-intensity interval training typically incorporates either running- or cycling-based modes of exercise and is an efficient exercise regimen for eliciting cardiopulmonary (23) and metabolic and neuromuscular (24) adaptations. In fact, Buchheit and Laursen (23) stated that HIIT "is today considered one of the most effective forms of exercise for improving physical performance in athletes" (p. 314). High-intensity interval training is often discussed in terms of duty cycles involving a high-intensity work phase followed by a lower-intensity recovery phase. It has been suggested that nine different HIIT variables can be manipulated to achieve the most precise metabolic specificity (23), including
- intensity of the active portion of each duty cycle,
- duration of the active portion of each duty cycle,
- intensity of the recovery portion of each duty cycle,
- duration of the recovery portion of each duty cycle,
- number of duty cycles performed in each set,
- number of sets,
- rest time between sets,
- recovery intensity between sets, and
- mode of exercise for HIIT.
The authors (24) indicate, however, that the intensities and durations of the active and recovery portions of each duty cycle are the most important factors to consider. To optimize HIIT training adaptations for athletes, HIIT sessions should maximize the time spent at or near O2max. More specifically, the cumulative duration and intensity of the active portions of the duty cycles should equate to several minutes above 90% of
O2max (24).
The benefits of a HIIT protocol designed to repeatedly elicit a very high percentage of O2max are primarily the result of the concurrent recruitment of large motor units and near-maximal cardiac output (6). Thus, HIIT provides a stimulus for both oxidative muscle fiber adaptation and myocardial hypertrophy. Additional HIIT adaptations include increases in
O2max, proton buffering, glycogen content, anaerobic thresholds, time to exhaustion, and time-trial performance. For example, Gibala and coworkers (63) reported equivalent improvements in muscle buffering capacity and glycogen content for HIIT at 250% of
O2peak during four to six 30-second cycling sprints compared to continuous cycling for 90 to 120 minutes at 65% of
O2peak over six total training sessions. In addition, 750 kJ cycling time trials decreased in both groups by 10.1% and 7.5% in the HIIT and long, slow endurance training groups, respectively. Thus, HIIT provided performance and physiological adaptations equivalent to those of long, slow endurance training, but in a time-efficient manner.
The strength and conditioning professional should consider a number of factors when designing a HIIT program. For example, a 400 m sprinter would need a HIIT program geared toward anaerobic-based durations and intensities more than a 2-mile (3,200 m) runner. Other considerations for the desired training adaptations are periodization, similar to that for resistance training, and the number of exercise sessions per day and week. Periodization allows for the general development of aerobic and anaerobic systems during the preseason with transitioning to sport-specific HIIT sessions during the competitive season. In addition, HIIT sessions in conjunction with other training sessions (i.e., team practices) may result in greater stress and risk for injury as a result of overtraining. Therefore, careful consideration is warranted in determining the appropriate number of HIIT sessions when concurrent with other sport-related activities.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Explore the various methods of applying chains to resistance training
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22).
One increasingly popular method of applying variable resistance is the addition of chains to traditional resistance training activities such as the bench press or back squat (4, 13, 39, 54). This method of force application is most popular among powerlifters (69, 70), but has become increasingly popular among strength and conditioning professionals working with a variety of sports (22). Despite the increasing popularity and the belief that these methods provide a training advantage, these beliefs are largely unsubstantiated in the scientific literature (13, 14, 39, 54). Some studies, however, demonstrate that the application of chains to traditional resistance training methods such as the bench press can be advantageous (6). Careful inspection of these studies reveals that the means by which the chains are applied to the free weight exercise may influence their effectiveness. Specifically, these studies used a method in which the chain was suspended from the bar without touching the floor until the athlete had reached the lowest position in the squat or until the bar had reached chest height in the bench press (6). While some research seems to support this methodology, much more research is needed to explore the various methods of applying chains to traditional resistance training methods.
Determining Resistance With Chains
The resistance provided by chains is largely dictated by the structure, density, length, and diameter of the chain and must be quantified before the chain is used in a resistance training setting. Additionally, the number of links in a chain will affect the amount of resistance provided by the chain (13, 55). To quantify the loading provided by chains, Berning and colleagues (13) developed a practical chart that related chain link diameter and length to the resistance load provided by the chain. This chart was later modified by McMaster and colleagues (54) to show the relationship between the chain mass, length, and diameter (table 16.1).
As a means of deciding on the barbell resistance to use in conjunction with chains, the absolute load is determined for the top and the bottom portion of the movement (4). The average of these two loads is then calculated and used to modify the barbell load in order to allow the athlete to train in the prescribed range.
As a general rule, Baker (4) recommends that the use of chains be reserved for experienced intermediate- and elite-level athletes who have stable exercise technique, as the addition of chains provides a loading challenge that can affect the athlete's technique.
Determining the Load to Use With Chains
To determine the load used with chains, the absolute chain resistance at the top and that at the bottom portion of the movement are summed and then averaged. For example, if athletes wanted to train at a 5-repetition maximum (5RM) load in the bench press, they would first determine the 5RM load without the chains. Then, if their 5RM is 120 kg (264 pounds), they would subtract the average chain resistance from this load. If at the bottom position the load is 0 kg and at the top the chain load is 11.1 kg (24.4 pounds), the average is 5.55 kg (12.2 pounds). Thus, the athlete would add 114 to 115 kg (251.8-253.0 pounds) to the barbell to achieve the appropriate loading.
Applying Chains to Free Weight Exercises
Generally, the application of chains to traditional resistance training methods allows for a linear increase in the applied resistance (54). Ways to apply chains include letting them touch the floor from the fully extended position during the movement (13) or hanging them from lighter chains (figure 16.1), which allows them to touch the floor only upon reaching the lowest portion (figure 16.2) of the movement pattern (i.e., bottom of the squat or at chest level during the bench press) (4, 6). Baker (4) suggests that the second method may affect the velocity of movement in three distinct ways. Firstly, the total barbell - chain complex comes into play only at the top of the movement (i.e., extend portion) when the chain links have been lifted off the floor. At the bottom of the movement, the links are in full contact with the floor, providing a reduction in load and allowing the athlete to accelerate the barbell at a faster rate. Secondly, it is possible that a within-repetition postactivation potentiation effect may occur in response to a greater neural activation. Specifically, when the chains pile on the floor and the mass of the barbell decreases, a greater neuromuscular activation may occur, allowing for an enhancement in movement velocity. Finally, it is possible that the decreasing resistance at the bottom portion of the movement may cause a more rapid stretch - shortening cycle. Baker (4) suggests that this happens in response to the eccentric unloading that occurs when the chain links pile on the floor at the bottom of the movement and a quicker amortization phase occurs when the athlete shifts from eccentric to concentric muscle action.
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.
Guidelines for agility training
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique.
Technical Guidelines and Coaching
In comparison to sprinting, change of direction and agility have a large number of degrees of freedom due to the multitude of movements that occur during a change of direction. Further, agility performance as restricted or determined by opponents or other tactical restraints and scenarios cannot be trained through the use of a single technique. Nevertheless, the following are some technical guidelines and coaching suggestions.
Visual Focus
- When changing direction in response to an opponent (either offensive or defensive), the athlete should focus on the shoulders, trunk, and hip.
- Following the anticipation of the event, unless deception is intended, the athlete should quickly redirect attention to a new area to help lead the transition of the body.
Body Position During Braking and Reacceleration
- Control the trunk leading into the deceleration (decrease large amounts of trunk motion) (70).
- Through the stance phase, reorient the trunk and hips toward the direction of intended travel to allow for a more effective reacceleration (15).
- Just as with acceleration mechanics, body lean is paramount in allowing proper force application through the ground with strong alignment of the ankle, knee, and hip and through to the trunk and shoulders.
- Enter and exit changes in direction with a lower center of mass; when performing side-shuffling changes of direction, maintaining this low center of mass is critical (78).
Leg Action
- Ensure that the athlete can effectively dissipate or tolerate the eccentric braking loads through an effective range of motion at the knee and avoid a stiff-legged braking style (81, 83).
- Emphasize "pushing the ground away" in order to enhance performance, especially while learning in closed drills. External focus of attention - through instructions to concentrate on the ground instead of a body part - has been shown to improve change-of-direction performance (64).
Arm Action
- Powerful arm actions should be used to facilitate leg drive.
- Ensure that the action of the arms is not counterproductive (i.e., does not cause a decrease in speed or efficiency), particularly during transitioning between difficult changes of direction (e.g., from a backpedal to a sprint).
Training Goals
The three goals of agility performance are enhanced perceptual - cognitive ability in various situations and tactical scenarios, effective and rapid braking of one's momentum, and rapid reacceleration toward the new direction of travel. To meet these goals, one should emphasize the following:
- Directing visual focus toward the opponent's shoulders, trunk, and hips to increase perceptual ability to anticipate the movement of a defensive or offensive opponent (75)
- Orienting the body into a position that allows for effective application of forces into the ground to maximize braking capacity, and increasing the speed from which one can rapidly stop as well as the direction of movement one must brake from (running forward, running backward, or shuffling laterally) (15, 70, 78, 83, 84, 86)
- The ability to maintain a good position after braking, reorient the body into a position that faces the new direction, and effectively use acceleration mechanics to reaccelerate (58)
Learn more about Essentials of Strength Training and Conditioning, Fourth Edition.