Forskning

August 9, 2011

Effect of caffeine on reactive agility time when fresh and fatigued

D M Duvnjak-Zaknich et al, Effect of caffeine on reactive agility time when fresh and fatigued, Medicine & Science in Sports & Exercise, 2011, Volume 43 (8).

This study examined the effects of acute caffeine ingestion on agility performance and decision making accuracy after simulated team-sport exercise. Using a randomized, double-blinded, counterbalance design, ten moderately trained male team-sport athletes ingested either 6 mg/kg caffeine or placebo 60 minutes before completing an 80 minute (4 x 20 minutes) simulated team-game, intermittent running protocol. Interspersed between each exercise quarter was a reactive agility test consisting of five trials where measures of total time, reactive agility time, decision time, movement time, and decision making accuracy were obtained. Although there were no significant differences between trials for total time, reactive time, movement time, or decision time, caffeine ingestion resulted in consistently faster total time, reactive time, movement time, and decision time scores compared with placebo condition for . These faster times were supported by qualitative analyses of “almost certain benefit” and large effect sizes for reactive time and “likely” to “very likely benefits” and moderate to large effect size for total time and reactive time. A “likely benefit” and moderate effect size was found for movement time, but the effect of caffeine on decision time was largely “unclear”, with small effect size and only a “likely” chance of benefit. Improved decision making accuracy after caffeine ingestion was supported by a “likely benefit” and large effect size. These authors conclude, ‘Caffeine ingestion may be beneficial to reactive time performance when athletes are fresh and fatigued’.