Citation

Duvnjak-Zaknich DM, Dawson BT, Wallman KE, Henry G. Med. Sci. Sports Exerc. 2011; 43(8): 1523-1530.

Affiliation

School of Sports Science, Exercise and Health, The University of Western Australia.

Copyright

(Copyright © 2011, Lippincott Williams and Wilkins)

DOI

10.1249/MSS.0b013e31821048ab

PMID

21266929

Abstract

PURPOSE:: This study examined the effects of acute caffeine ingestion on agility performance and decision-making accuracy following simulated team-sport exercise. METHODS:: Using a randomized, double-blinded, counter-balanced design, ten moderately trained male team-sport athletes ingested either caffeine (6 mg·kg) or placebo (dextrose) 60 min before completing an 80 min (4 × 20 min) simulated team-game, intermittent running protocol. Interspersed between each exercise quarter was a reactive agility test (RAT) consisting of five trials where measures of total time (TT), reactive agility (RA) time, decision time (DT), movement time (MT) and decision-making accuracy were obtained. RESULTS:: While there were no significant differences between trials for TT (P = 0.54), RA time (P = 0.84), MT (P = 0.89) or DT (P = 0.91), caffeine ingestion resulted in consistently faster TT (2.3%), RA time (3.9%), MT (2.7%) and DT (9.3%) scores compared to placebo (significant main effect for condition for RA time, TT, DT and MT; P < 0.05). These faster times were supported by qualitative analyses of 'almost certain benefit' and large effect size (ES) for RA (quarter 3) and 'likely to very likely benefits' and moderate to large ES for TT (pre circuit, quarters 1, 2 and 4) and RA time (pre-circuit, quarters 1, 2 and 4). A 'likely benefit' and moderate ES was found for MT (quarters 1 and 3), but the effect of caffeine on DT was largely 'unclear', with small ES and only a 'likely' chance of benefit (quarter 2 and 3). Improved decision making accuracy (3.8%) after caffeine ingestion was supported by a 'likely benefit' (quarter 1) and large ES (quarters 1 and 4). CONCLUSION:: Caffeine ingestion may be beneficial to reactive agility performance when athletes are fresh and fatigued.

Language: en