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Nutrition > Theory to practice - Effect of dehydration on skill performance in team sport players
Theory to practice - Effect of dehydration on skill performance in team sport players
Issue: Volume 29 Number 4
Background
Success in skill sports such as netball, basketball, hockey and all the football codes, requires high levels of concentration, alertness and focussed attention. This is due to the dynamic and rapidly changing situations players are faced with while exercising at high intensity with infrequent and often short breaks in play. Vigilance is a player's ability to sustain a high level of alertness for an extended period of time. Numerous studies have shown that dehydration affects perceived fatigue and/or mental performance during endurance exercise. However, no study has examined the effects of dehydration on vigilance in team sport athletes such as basketball players. The purpose of this American study was to determine the effects of dehydration on vigilance in 17 to 28 year old male basketball players.
Research
Each of the basketball players (17-28 yr) did what is called a Test of Variables of Attention (TOVA) at baseline (test 1), after walking on a treadmill (60% max heart rate) in the heat (40°C and 20% relative humidity) (test 2), and then after a simulated basketball game (test 3). Test 1, the TOVA, consisted of each athlete sitting in front of a computer for a total of 21.8 min for four quarters (5.45 min each). On the computer screen, two different visual stimuli were presented (one at a time) on the screen for 100 ms at 2-s intervals in a fixed random order. The stimuli were white squares and differed only in that the target had a black hole near the top and the non-target had a black hole near the bottom. Players were asked to press a handheld button only when the target square appeared on the screen, not the non-target square. For test 2, the athletes then walked on a treadmill (60% maximum heart rate) in the heat (40°C and 20% relative humidity) for 9 x 15 min periods separated by 5 minutes rest and then did the test again after a simulated basketball game (test 3) done 50 minutes after the treadmill walk. Tests 2 and 3 were performed while subjects were either dehydrated (1-4% body weight) or normally hydrated.
Findings
Vigilance-related attention of the basketball players was impaired by dehydration. These results suggest that fluid replacement is essential to prevent the decline in vigilance that occurs with dehydration in highly dynamic environments. Therefore, team sport players are strongly advised to maintain hydration status for optimal concentration and maintenance of skills during competition.
Coach's takeout
In agreement with research on endurance runners, swimmers, cyclists and rowers, these results suggest that performance is impaired with dehydration. In team sports where the playing environment is so dynamic and changing continuously, requiring players to stay focussed and vigilant the whole game, ensuring that players are hydrated before the game, replace fluids during the game, and drink to recover back normal body weight after the game, is essential, especially when playing an a tournament situation.
Reference
Baker, LB, Conroy, DE, Kenney, WL 2007, 'Dehydration impairs vigilance-related attention in male basketball players', Medicine & Science in Sports & Exercise, 39(6), pp.976-983.
