出版社:Instituto Brasileiro de Pesquisa e Ensino em Fisiologia do Exercício
摘要:Background: CrossFit is a modality of high intensity exercise with an increasing popularity. Furthermore, the rising use of nutritional supplements by amateurs and professional athletes of elite sports bring up a new discussion for the safety of both practices. Here, we aim to evaluate whether use of nutritional supplements by CrossFit athletes affect normal renal function. Materials and Methods: We used male CrossFit athletes separated into three groups: a control (C) and a nutritional supplement user group (NSU), and an additional group with NSU who were on a diet (NSDU). The creatinine and urea levels were obtained by two isolated samples of urine (pre and post training) and then analyzed by spectrophotometry. A t test was applied to verify possible differences between C, NSU and NSDU groups. Results: The most used nutritional supplements were creatine and whey protein, and 8 of NSU declared to be on a high protein diet (forming NSDU group). Creatinine levels significantly increased after training, but not urea levels, and samples above normal range were frequently observed after training. However, comparison of creatinine and urea levels among C, NSU and NSDU groups showed no statistical difference in pre and post training conditions. Conclusion: Our data suggest that the use of nutritional supplements and high-energetic diets did not significantly affect urinary creatinine and urea levels, and that the clinical alterations observed here are probably related to a transitory effect of high-intensity training as CrossFit.