Explaining variation in sweat sodium concentration: effect of individual characteristics and exercise, environmental, and dietary factors

Abstract

This comprehensive analysis of a large, diverse data set contributes to our overall understanding of the factors that influence whole body sweat [Na + ]. The main finding was that energy expenditure was directly associated with whole body sweat [Na + ], potentially via the relation between energy expenditure and whole body sweating rate (WBSR). Warmer months (proxy for heat acclimatization) were associated with lower whole body sweat [Na + ]. Exercise mode, air temperature, and sex may also have small effects, but other variables (age group, race/ethnicity, fluid balance, sodium intake, relative V̇o 2max ) had no association with whole body sweat [Na + ]. Taken together, the models explained 17%–23% of the variation in whole body sweat [Na + ].