Changes in Water Turnover and Its Components Over One Athletic Season: An Observational Study Among Athletes From Different Sports

Le résumé fourni par la source

BACKGROUND: Water turnover (rH2O) is related to water balance including preformed water intake (WI), metabolic, inspired, and transcutaneous water. Literature is scarce on athletes. This study aimed to estimate and compare rH2O and its components during one athletic season (preparatory and competition phases), adjusting for body composition and energy expenditure (EE). METHODS: This longitudinal observational study included 112 athletes (19.8 ± 4.9 years, 39 females). Doubly labeled water determined total EE, rH2O, and the remaining components through specific equations. Total body water was determined by deuterium dilution and fat-free mass by the four-compartment model. Resting EE was assessed by indirect calorimetry. RESULTS: During the preparatory phase, male athletes showed higher rH2O [5.03 (0.14) kg/day] compared with females [3.64 (0.19) kg/day, p < .001], even adjusting for body mass (p = .024), but not for fat-free mass, total body water, and EE. Triathletes showed higher values of rH2O after adjustments (p < .05). Over the athletic season, no changes occurred for rH2O or preformed WI within or between sexes or sports, even adjusting for body composition while some changes occurred adjusting for EE (p < .05). Over the season, metabolic water increased (p < .001), while inspired and transcutaneous water showed both increases and reductions (p < .05). A small prevalence (∼16%) of low WI (WI ≤ 35 ml/kg of body mass/day) was persistent in both timepoints. CONCLUSION: While rH2O and preformed WI did not differ over the season, cross-sectional differences were observed between sports but not between sexes, highlighting the variability of rH2O and impact of contributing factors. Low preformed WI was present throughout the athletic season.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.