Tennisology
Inside the Science of Serves, Nerves, and On-Court Dominance
208 Pages, 6
Thought provoking and original, Tennisology delves into the science, psychology, and history of the world's most popular individual sport in search of the factors that truly influence successful on-court play. The findings will not only surprise you but also change the way you approach the game.
Based on the latest research, statistics, and analysis, Tennisology provides fascinating insights and observations on development, conditioning, and performance:
• How and when the skills of the game are best learned
• Why pressure affects some players but not others
• Whether observing others can improve individual play
• Whether there is a link between player personality and style of play
• How and why height influences serve velocity
• Whether great players are born or developed
You will also discover how to apply the laws of physics to improve accuracy and consistency of shots and serves; how to structure training to minimize fatigue in lengthy matches; and how technology has affected the way the game is played, officiated, and coached.
From the historical roots of modern tennis to the physical attributes that define the game, Tennisology will captivate you and make you think. It is a must-read for passionate players, coaches, and fans alike.
Chapter 1 Evolution of the Sport
Chapter 2 Court Lessons for Life
Chapter 3 Learning the Game
Chapter 4 Nature vs. Nurture on the Court
Chapter 5 Player Development
Chapter 6 Physics of Tennis
Chapter 7 Tennis Technology
Chapter 8 Trained Tennis Body
Chapter 9 Visualization Techniques
Chapter 10 Match Mind-Set
Thomas Rowland is the director of pediatric cardiology at the Baystate Medical Center in Springfield, Massachusetts. He serves as a professor of pediatrics at Tufts University School of Medicine and was a past adjunct professor of exercise science at the University of Massachusetts.
Rowland is the author of two books, Children’s Exercise Physiology, Second Edition, and The Athlete’s Clock. He has served as editor of the journal Pediatric Exercise Science and president of the North American Society for Pediatric Exercise Medicine (NASPEM) and was on the board of trustees of the American College of Sports Medicine (ACSM). He is past president of the New England chapter of the ACSM and received the ACSM Honor Award in 1993.
Rowland is a competitive tennis player and distance runner. He and his wife, Margot, reside in Longmeadow, Massachusetts.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.
Physical Demands of Tennis
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases.
Sport scientists have demonstrated the detrimental effects of fatigue during extended tennis play. After about an hour of tennis play, hitting inaccuracy, unforced errors, and mental mistakes begin to creep in; serve and stroke velocity decline; and speed of running to the ball decreases. Oliver Girard and colleagues of the faculty of sport science at the University of Montpelier examined the maximal force of leg contraction, leg stiffness, jumping height, and muscle soreness in 12 well-trained tennis players before, after, and every 30 minutes during a 3-hour competitive match.6 Leg force declined by almost 10 percent during play. Jumping ability stayed stable during play but declined 30 minutes afterward. Both muscle soreness and rating of perceived exertion (i.e., how tired the players felt) increased progressively during the match.
Interestingly, studies on the effect of prolonged tennis play (or simulated conditions) on performance have not always been consistent, and some case findings have been inexplicably conflicting. In one study, for instance, fatigue reduced accuracy of tennis strokes by as much as 81 percent. In a review of this subject, however, Daniel Hornery and colleagues at the Australian Institute of Sport in Canberra concluded that "under physiological strain, stroke accuracy is largely maintained whereas stroke velocity is more likely to deteriorate".8 Some authors have found very minimal effects of fatigue on tennis performance. Hornery and colleagues suggested that such discrepancies might reflect the methodological limitations of these studies, including inadequate assessment of the multifaceted skills involved in tennis that contribute to performance, the use of nontennis interventions to cause fatigue, and levels of fatigue that did not simulate those expected to occur in real match play.
Nevertheless, the physical demands of tennis can be extreme, especially at the professional level. In a 6-hour slugfest - the longest final in the 107-year history of the Australian Open - Novak Djokovic came out on top 5-7, 6-4, 6-2, 6-7(5) 7-5 over Rafael Nadal. Both players were near collapse at the final point. "I'll never forget this match," said Nadal afterward.
If players want to learn techniques for preventing deterioration of performance due to fatigue, they must first understand what causes fatigue in the first place. Researchers have carefully analyzed the characteristics of a typical tennis match at high levels of competition.
- During a tennis match, the time spent actually playing is approximately 20 to 30 percent greater on clay courts than on faster court surfaces.
- Play is intermittent and consists of work periods of 5 to 10 seconds. These periods are interrupted by 10 to 20 seconds of rest and by pauses of 60 to 90 seconds during court changeovers.
- On average, each player strikes the ball 2 to 3 times per rally.
- From the ready position, 80 percent of balls are struck within 2.5 meters. The player moves 2.5 to 4.5 meters in approximately 10 percent of strokes and more than 4.5 meters in 5 percent of strokes.
- In the course of a point, a player runs an average of 8 to 12 meters and changes directions 3 to 5 times.
- Serves account for 12 to 18 percent of total strokes during service games.
- A serve-and-volley player moves forward 20 to 40 percent more than does a baseline player, who moves laterally 60 to 80 percent of the time.
Sources: Mendez-Villanueva et al.,13; Johnson and McHugh9; Roetert and Kovacs18; Groppel and Roetert7.
Tennis is a game of repetitive short, high-intensity sprints that often require explosive strength (i.e., quick steps and leg push-off) along with muscular force at the shoulder and upper extremity when striking the ball. These are coupled with the need for a high degree of mental focus, visuomotor timing, and attention to visual tracking. The player must repeat all of these activities over the course of about two hours (or sometimes five hours or even more in professional play). Also, in some tournament settings players may be called on to compete in successive matches with limited time for rest and recuperation.
Learn more about Tennisology.
The Science of Spin
Everywhere, things spin - heavenly bodies, subatomic particles, children’s toys, gyroscopes. Spinning is a fundamental action of the natural world.
When applied to a tennis ball, spin creates uneven forces that alter the course of the ball through the air. A spinning ball can skid at midcourt or cause a lob headed for the players' box to suddenly drop like a stone on the service line. It is almost impossible to strike a ball without applying any spin whatsoever, but manipulating strokes by purposefully applying spin can make one a master of the game.
Our understanding of spin comes from Daniel Bernoulli, an 18th century mathematician working at the University of Basel. Bernoulli's principle states that the faster a gas or fluid is flowing, the lower its pressure. This principle is best explained in terms of how airplanes fly. The wing of a 747 is cambered so that the curvature is greater on the top than on the bottom. Because the same amount of air flows over both the top and bottom of the wing as the plane flies, the air on top must flow faster. (It has farther to go due to the curvature, yet in the same time duration as the air beneath the wing.) According to the principle, the slower-moving air on the bottom has greater pressure than the air on the top, and the wing is pushed up.
Topspin
The same thing happens when a tennis ball is made to spin as it sails across the court. Imagine you're looking at the ball from the side and it's moving from left to right. If the ball is not spinning, the air pressure above and below the ball will be equal and the only action in the vertical direction will be gravity, which causes the ball to fall as it passes over the net. But if a player hits a forehand so that the ball is spinning counterclockwise from your viewpoint, the air just at the surface of the ball will be spinning as well. The air at the top of the ball directly meets the surrounding air as the ball travels, sort of like a headwind. Conversely, the air attached to the bottom of the ball moves in the same direction as the air it meets, like a tailwind. As a result, the air at the bottom of the ball travels faster than that at the top. According to Bernoulli, the pressure on the top of the ball will be greater than that underneath as it flies over the net. This will make the ball dive, or curve downward, rather than follow a straight path (figure 6.1).
http://www.humankinetics.com/AcuCustom/Sitename/DAM/117/E6177_480251_ebook_Main.png
The Bernoulli effect when a ball is hit with topspin.
Reprinted from J. Groppel, 1992, High tech tennis, 2nd ed. (Champaign, IL: Human Kinetics), 111, by permission of the author.
That's topspin. Applying this type of rotation to the ball causes it to land short of where it would by gravity alone. Then, when the ball does strike the court, another altered action takes place: It bounces higher. As discussed previously, the angle at which a ball rebounds is normally about the same as the angle at which it hits the court. If it arrives at 60 degrees relative to the near court, it departs at 60degrees relative to the far court. However, a ball hit with topspin comes down more vertically than a ball that's not spinning does. Consequently, it rises more abruptly. When the ball is struck briskly, it bounces up with greater speed.
Topspin is created when a player sweeps the racket face up and over the top of the ball. A ball hit is this fashion dips up (because the racket face moves up to strike the ball), falls shorter, and rebounds higher and with greater velocity. The ball can be struck safely by the player with greater velocity.
Among the most common mistakes that a tennis player commits are vertical errors, or errors of depth. The ball must be struck within the angular window of acceptance, defined as the range of angle of the ball leaving the racquet that will allow it to both cross safely over the net yet still land in the opponent's court. This window is affected by several factors, including the height of the contact point, where on the court the ball is struck, and - most important - how hard the ball is hit. Physicist Harold Brody discovered that the window of acceptance shrinks by about half when a ball is struck at a speed of 70 mph compared to that leaving the racquet at 50 mph.1,2 This means that slowing the velocity of the ball improves the chances for a good shot. However, no player wants to help his opponent by slowing the ball. This is where topspin helps. Using topspin, the player can hit the ball harder but the window of acceptance will not decrease as much as it would with a flat stroke because the ball will be less likely to go long. Topspin makes the ball drop earlier and keeps hard-hit strokes in the court.
Björn Borg was the first real master of topspin, and with his enormous success the shot quickly caught on. Borg had his rackets strung extremely tightly - a tension of about 80 pounds per square inch. His powerful shots would rise to pass about 6 feet (1.8 m) above the net but then rapidly plummet to drop well within the baseline. His opponents said it was impossible to get any rhythm going against him while defending shots like that. Today's game, with its emphasis on power shots delivered from the baseline that Borg pioneered, would be quite impossible without reliable topspin to keep the ball in the court.
Learn more about Tennisology.
Mental Imaging
Why waste money on Wimbledon tickets when you can imagine a perfect serve?
Why waste money on Wimbledon tickets when you can imagine a perfect serve? We humans are capable of manufacturing moving pictures in our brains, so why not let motor neurons observe the mind's own visual images to improve your service technique?
Mental imaging is the technique of repeatedly projecting in one's imagination the act of tennis play. Mental imaging has been around for a long time - not just in sport but also in such diverse realms as education, medicine, and music - and many people are convinced that it works. Hundreds of research studies have been performed in an attempt to verify this conclusion (but, unfortunately, most of these studies are considered to be of low scientific quality). There even exists an electronic journal - Journal of Imagery Research in Sport and Physical Activity - that is devoted to the subject. Sport psychologist Robert Weinberg at Miami University wrote an article titled "Does Imagery Work?" After reviewing all studies examining the efficacy of mental imagery, he concluded that "the weight of all this evidence most certainly would point to the fact that imagery can positively influence performance."20
In mental-imaging studies, participants are typically randomly assigned to one of three experimental conditions: imagery with a positive outcome (e.g., a service ace), imagery with a negative outcome (e.g., a double fault), and control (nonimaging). Most investigations of this type indicate that mental rehearsal of a positive outcome improves performance, whereas negative imaging leads to deterioration. Just how or why mental imaging works remains a mystery. It's possibly all a matter of stimulating motivation. However, fMRI does reveal that objective changes in particular brain centers can be observed when an individual performs mental imaging. This suggests that any positive effects of mental imaging are more than psychological. Evidence also suggests that, in addition to directly improving performance, mental imaging might enhance mental skills that influence performance. For example, it might increase self-confidence, suppress competitive anxiety, and improve motivation.
However, because this body of research certainly has its limitations, the final answer regarding the efficacy of mental imaging isn't in. Some studies have assessed the effects of mental imaging when used just before an athletic competition rather than as a training tool. In such studies, the specific effectiveness of mental imaging is often difficult to isolate because it was used along with other mental skills, such as relaxation. It is difficult to verify whether the research participants actually used valid imaging techniques, and very few studies have been conducted in real competitive situations.
Also, not all research information on mental imaging in tennis is consistent. For example, Ricardo Weigert Coelho and colleagues at the Research Center for Exercise and Sport Science at the Federal University of Paraná in Brazil demonstrated that a combination of observation and mental imagery improved serve accuracy in national-level 16- to 18-year-old tennis players but that this intervention had no effect on skill in the serve return.4 The authors felt that this finding was consistent with the idea that the athlete can precisely visualize the serve in his mind because it is a predictable motion that the server controls. The serve return, on the other hand, is unpredictable and thus cannot be so easily imagined visually.
However, Nicolas Robin and colleagues in the Laboratoire Performance, Motricite et Cognition in Poitiers, France, showed that 15 sessions of imagery training improved the accuracy of serve returns in experienced French players.14 This study also examined the extent to which a player has the ability to create mental images. They found that good imagers (as determined by a questionnaire) had better results than poor imagers, although the latter still showed more improvement than nonimaging participants.
The general consensus is that these investigations support the idea that repeated mental imaging of a motor task or complex sport skill can improve performance of that task or skill, at least to some extent. However, these studies suggest that mental imaging is not as effective as physical training, so one still has to put in the hours of organized practice. But, for many people, mental imaging appears to help.
The following tips and guidelines might help optimize your ability to gain skill via mental visualization training.
- Create an image of tennis play as viewed from the stands or put yourself right into the action on the court. While you yourself might be the player you are portraying in this brain video, it is probably best to use your favorite professional tennis player, who is likely a superior model.
- Don't just close your eyes and watch your mind's imagery - get right in there and make it real. Sense the kinesthetic motion of your muscles as they move. Feel the heat and sweat. Hear the crowd roar and the racket striking the ball.
- Perform mental imaging in a peaceful environment for at least 15 minutes 2 or 3 times a week.
- Studies indicate that mental imagining can be effective in youths as well as the elderly.
- Watch it as the action occurs. Researchers initially believed that imagining in slow motion was better because it allowed more time to focus on different parts of the physical act. Now, however, most sport psychologists feel that you should imagine in real time because you want your brain to learn the motion as you're going to use it - at full speed.
- Try it with some soothing Debussy or Tchaikovsky. At least one study suggests that background music may make mental imaging more successful.
Learn more about Tennisology.