Effects of Creatine Supplementation in the Concentrations of Creatine Kinase, Creatinine, Urea and Lactate on Male Swimmers

The purpose of this study consisted in analyzing the alterations in samples of Creatine Kinase (CK), Creatine and Urea, in male swimmers under creatine supplementation. Seventeen athletes took part in a sequence of tests in a swimming pool (8 x 100 m freestyle) with progressive sets starting at 65 leading up to a 100% maximum capacity sets. The athletes were evaluated immediately before and after the tests (5 min), in order to obtain levels of CK, Creatine and Urea concentrations. After 6 days of supplementation with Creatine (20 g/ day) + maltodextrin (1 g/kg/day) or nothing but maltodextrin control (1 g/kg/day), new tests similar to the initials, were performed. The variables were analyzed by non-parametric tests of Wilcoxon (in the same group) and Mann-Whitney (between the groups). In statistical terms, a significant level was established: p< 0.05. On CK it was observed, after supplementation, a statistically significant increase in the Creatine group at rest (172.83 mg/ul ± 2.43 to 326.42 mg/ul ± 13.69) and in the end of the tests (202.32 mg/ul ± 21.85 to 363.33 mg/ul ± 20.53). The same occurred with the creatine concentration at rest (1.05 mg/dl ± 0.12 to 1.27 mg/dl ± 0.20) and in the end of the tests (1.23 mg/ dl ± 0.23 to 1.53 mg/dl ± 0.26) with the only tendency of a significant comparison with the control group (p = 0.06). Significant differences in urea concentrations were not observed.