Is sweat rate during steady state exercise related to maximum oxygen uptake?

Abstract

The purpose of this study was to investigate whether whole-body sweat rate induced by exercise (SR ex) at the same oxygen uptake could be correlated with individual maximum oxygen uptake (peak oxygen uptake ( V ˙ O 2 peak ) ). A secondary purpose was to examine the relationship between SR ex and local sweat rate induced by pilocarpine on the forearm at rest (SR pilo). Nine healthy young males ( V ˙ O 2 peak 55.2 (12.3) mL min −1 kg −1, mean (SD); 43.3–76.1 mL min −1 kg −1, range), acclimatized to a tropical climate had their sweating stimulated in two situations: (1) exercise-induced whole-body sweat by 120 min of cycling exercise at a constant submaximal oxygen uptake of 1.65 L min −1 or (2) pilocarpine-induced sweat on the right forearm with 0.5% pilocarpine hydrochloride (1.5 mA, 5 min) at rest. The SR ex was not correlated with V ˙ O 2 peak ( r = - 0.53 , p = 0.14 ). In addition, there was not correlation between SR ex (0.38 (0.03) mg cm −2 min −1) and SR pilo (0.36 (0.20) mg cm −2 min −1) ( r = 0.23 , p = 0.57 ). These results suggest that whole-body sweat rate during exercise at the same oxygen uptake in a temperate environment is not related to V ˙ O 2 peak . Furthermore, the eccrine sweat gland does not respond similarly for local pilocarpine or exercise stimuli.