Abstract
The purpose was to determine differences in acute and chronic hydration status in female student-athletes (n = 40) practicing in moderate, dry conditions (17–25 °C, 30–57% humidity) indoors and outdoors. Body weight and urine samples were recorded before and after exercise as well as fluid intake. Sweat rates expressed as median and interquartile range did not differ, but fluid intake was significantly higher during indoor (0.64 [0.50, 0.83] L/h) vs. outdoor conditions (0.51 [0.43, 0.63] L/h), p = 0.001. Fluid intake compensated for indoor sweat rate but not outdoors. When exercising indoors, 49% of the student-athletes reported urine specific gravity (USG) values >1.020, and 24% of the day after morning samples were scored ≥4 on the color chart rating. The percentages increased to 58% and 31%, respectively, when exercising outdoors (p > 0.05). Thus, fluid intake was higher indoors vs. outdoors but sweat rate did not differ among athletes. Yet, chronic hydration status was impaired in more than 50% of the student-athletes with a discrepancy between USG scores and urine color scores identifying underhydration. This suggest that 24-h fluid intake should be taken into account and that hydration protocols may need to be tailored individually based on urine USG values. Practice location (indoors vs. outdoors) may further complicate hydration protocols.
Highlights
Athletes are advised to consume enough fluid to stay in a well-hydrated state in order to maintain peak exercise performance [3]
The aim of this study was to determine potential differences in acute and chronic hydration status (e.g., urine specific gravity (USG) and urine color (Uc)) in student-athletes exercising in different environmental conditions
Complete indoor and outdoor data were obtained for 40 student-athletes and these data were used for all analyses
Summary
Athletes are advised to consume enough fluid to stay in a well-hydrated state in order to maintain peak exercise performance [3]. The hindrance of performance when athletes are improperly hydrated is widely accepted, especially when the net body weight loss due to exercise-related sweating exceeds more than 2% of body mass [4,5]. Even slight levels of underhydration, as small as 1% of total body weight loss [4], cause a myriad of problems in athletes across all sport types [6,7,8,9]. Loss of body water, resulting in dehydration, raises plasma osmolality levels which in turn stimulates the release of vasopressin, reducing the amount of water lost through the kidneys [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
