Isotonic sports drink promotes rehydration and decreases proteinuria following karate training

Abstract Introduction: Adequate hydration status in the sport is essential for good health, yet the relationship between hydration, proteinuria and sports is little studied. Objective: To analyze the influence of an isotonic sports drink as rehydration strategy on the hydration status and proteinuria after karate training. Methods: Ten athletes participated in this study. In the first session of standard training, called observation training session (STO), the athletes hydrated themselves according to their habits, and in the second session of standard training, called nutritional intervention training session (STIN), an ideal practice of hydration protocol was followed, using an isotonic sports drink as a rehydration liquid during the training. The hydration status was verified by monitoring the body weight before and after training, the urine specific gravity pre-and post-training and the urine volume post-training. To observe the influence of practice of hydration on the renal function post exercise proteinuria was measured. Results: We observed a statistically significant difference in urine density between the samples pre- and post-exercise only on STIN (p = 0.047). When we compare the sessions, there was a lower variation in body weight (p = 0.011) and higher urinary volume (p < 0.001), on nutritional intervention training. In STO, there was a higher percentage of athletes who showed proteinuria (70%) compared to the STIN (50%) in the urine sample after training. Conclusion: The use of isotonic sports drink as practice of hydration by karate athletes promoted rehydration during one session of training and reduce post-training proteinuria.