Normative Data for Sweating Rate, Sweat Sodium Concentration and Sweat Sodium Loss in Female Athlete

The testing procedures will follow the standardized Gatorade Sports Sciences GSSI sweat testing protocol using the absorbent sweat patch technique, to measure local sweat \[Na+\], which will be normalized to whole-body sweat \[Na+\]. Whole-body sweat rate (WBSR) will be calculated based on changes in exercise body mass, pre to post training, and adjusted for food and fluid intake, as well as urine and stool loss. The rate of sweat sodium loss (RSSL) will be determined as the product of sweat \[Na+\] and WBSR. Secondary outcomes are pre-exercise hydration status measured by urine specific gravity (USG) and estimation of menstrual cycle phase collected by self-report date of last menstrual cycle. Athletes will complete a single day of testing, unless a repeat test is requested by the team's performance staff. In this case, athletes will undergo the exact same protocol as described above.