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.

摘要：运动过程中维持充足的水合状态（hydration status）对身体健康至关重要，但目前针对水合状态、蛋白尿（proteinuria）与运动三者间关联的研究仍较为匮乏。研究目的：分析以等渗运动饮料（isotonic sports drink）作为补液策略时，空手道训练后运动员的水合状态与蛋白尿水平的变化情况。研究方法：本研究共招募10名运动员参与。在第一次标准训练（命名为观察性训练场次STO）中，运动员按照自身日常习惯进行补水；在第二次标准训练（命名为营养干预训练场次STIN）中，运动员需遵循标准化补水方案，训练全程以等渗运动饮料作为补液饮品。本研究通过监测训练前后的体重（body weight）、训练前后的尿比重（urine specific gravity）以及训练后的尿量（urine volume），对运动员的水合状态进行评估；同时通过检测运动后蛋白尿水平，分析补水方式对肾功能的影响。研究结果：仅在营养干预训练场次STIN中，我们观察到运动前后的尿比重差异具有统计学意义（p=0.047）。对比两次训练场次可知，营养干预训练场次中运动员的体重变化幅度更低（p=0.011），尿量更高（p<0.001）。在训练后采集的尿液样本中，观察性训练场次STO中出现蛋白尿的运动员占比达70%，高于营养干预训练场次STIN的50%。研究结论：空手道运动员采用等渗运动饮料进行补水，可在训练过程中实现有效补液，并降低训练后蛋白尿的发生水平。