Estimation of sweat rates during cycling exercise by means of the closed chamber condenser technology.

Abstract

Knowledge of local sweating patterns is of importance in occupational and exercise physiology settings. The recently developed closed chamber condenser technology (Biox Aquaflux® ) allows the measurement of evaporative skin water loss with a greater measurement capacity (up to 1325 g/h/m2 ) compared to traditional evaporimeters. The aim of this study was to evaluate the applicability of the Biox Aquaflux® to estimate sweat production during exercise. Fourteen healthy subjects performed a 20-min cycle ergometer trial at respectively 55% heart rate (HRreserve and 75% HRreserve . Sweat production was estimated by measuring body weight before and after exercise, by calculating the amount of sweat collected in a patch, and by measuring the water flux (in g/h/m2 ) with the Biox Aquaflux® instrument. The Biox Aquaflux® instrument allowed the follow up of sweat kinetics at both intensities. Correlations between the measurement methods were all significant for the 75% HRreserve trial (with r ranging from 0.68 to 0.76) whilst for the 55% HRreserve a significant relation was detected between the patch method and the Biox Aquaflux® only (with r ranging from 0.41 to 0.79). The Biox Aquaflux® instrument is a practical and direct method for the estimation of local sweat rates under field conditions.