CAFFEINE IMPROVES 50-m SWIM PERFORMANCE IN SOME SWIMMERS
Hill, M. R. (2006). Low dose caffeine use to improve 50-meter swimming performance. Medicine and Science in Sports and Exercise, 38(5), Supplement abstract 1334.
This investigation determined if a low dosage level of caffeine (2 mg/kg body mass) could improve swimming performance in 50-m swimmers. Elite male (N = 8) swimmers (including four Olympians) performed two 50-m swims. Ss participated in one swim at 07:00 and another at 17:00 in a random double blind, cross-over design. Ss ingested 2 mg/kg body weight of 99.9% pure caffeine or equivalent placebo doses 60 minutes prior to each swim. Off-block times, 15-m time, and 50-m times were calculated to the nearest 0.01 seconds. Ss were asked to abstain from all caffeine use for two days before the study. Athletes were also given a 7-point Likert scale post-swim questionnaire to determine each S's normal caffeine use, previous day's training, and feelings during the assessed swim (mood, technical skill, concentration, decision-making, reactions, and performance).
The pre-race questionnaire showed that all Ss believed that caffeine could improve swim performance. Ss consumed approximately 91 mg of caffeine 2.2 times per day. There were no differences between conditions for off-block times, 15-m swim times, and 50-m swim times. The post-race questionnaire indicated that the S's technical skill level was higher during the caffeine trial relative to the placebo trial. Concentration, decision-making, and rating of swim performance were not different between conditions. S's swim mood and feelings of sharpness/reactions were unchanged in the caffeine relative to placebo trials, respectively.
Implication. A caffeine dose of 2 mg/kg body mass did not significantly improve 50-m swimming time in elite swimmers. Although 6 out 8 athletes improved their swimming times and felt that it contributed to their overall performance, caffeine use appears to affect each athlete individually and thus caution should be made concerning its use in competition. Caffeine potentially is sprint-performance improving for some swimmers.