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.