Objectives.—The purpose of this study was to determine the influence of short-term creatine supplementation on sprint swimming performance (50 and 100 m) 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 (Beforeperiod: 53.1±3.73 s, after-period: 50.7±2.84 s). 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.
