The effects of creatine supplementation on performance and hormonal response in amateur swimmers

摘要

Objectives. - The purpose of this study was to determine the influence of short-term creatine supplementation on sprint swimming performance (50 and 100m) and hormonal responses (growth hormone, testosterone and cortisol).Methods. -Twenty amateur male swimmers ingested creatine monohydrate (CR) or a matched placebo (PL) for 6 days. All subjects performed 6 days, swimming exercise. The subjects were tested for performance and hormonal responses the day before and after this creatine loading. Results, -The mean swimming time of CR group in 50m was significantly decreased (Before-period: 53.1 +-3.73s, after-period: 50.7+-2.84s). Growth hormone and cortisol were not affected by this creatine loading. But, testosterone concentration was significantly greater in CR compared to PL after supplementation period (P<0.05).Conclusions. -Our data suggest that short-term creatine supplementation has improved 50m sprint performance in amateur swimmer and it seems unlikely creatine loading is hormonally mediated.