Effects of Water-loading Weight Loss on the Physiological Response in College Wrestlers

Abstract

PURPOSE: The purpose of this study was to evaluate the effects of water-loading weight loss on physiologic response.METHODS: Thirteen consenting university wrestlers (weight 71.5±8.0 kg, BMI 25.0±2.0 kg/m²) randomly divided into the weight loss (WL) group (n=6) and water-loading weight loss (WWL) group (n=7). Wrestlers performed 2-week weight loss program targeting average of 5-10% of body weight reduction, under the supervision of a coach. Participants were instructed to drink 1.5-2 L and 6-7 L daily during the first week in the WL and WWL groups, respectively. Both groups were gradually reduced water intake and didn’t drink water the day before weighing. Anthropometric characteristics, hematocrit (HCT), serum electrolytes, aldosterone, and cortisol were measured before and after weight loss. Data were analyzed with two-way ANOVA using SPSS. The significance level was set at p<.05.RESULTS: After 2 weeks, the weight (p=.004), BMI (p<.001), lean body mass (p<.001), body water composition (p<.001), and SBP (p=.046) were reduced significantly in both groups. However, there was no statistically significant between-group difference in all parameters of body composition and SBP. The HCT and chloride (Cl-) decreased in both WL and WWL groups (p=.018 and p=.006, respectively). Serum aldosterone and cortisol significantly increased in both groups (p<.001). In particular, cortisol was significantly lower in the WWL than in WL group.CONCLUSIONS: This study suggested that a large-volume hydration before water restriction for weight loss can be a safe method.