Relationship between sweat gland recruitment and esophageal temperature during exercise-induced hyperthermia

Abstract

1. This study found four distinct phases of sweat gland recruitment could be identified during exercise-induced hyperthermia. 2. First, at rest there were no detectable active sweat glands. Second, as esophageal temperature increased consequent to the exercise bout, a threshold was reached and sweat gland recruitment was initiated. Next, sweat gland recruitment increased linearly with the increase in esophageal temperature ( r=0.78). Lastly, the number of active sweat glands reached a plateau at a maximum value. 3. These data support the hypothesis that sweat gland recruitment fits a proportional control model similar to other known thermoregulatory effectors. Furthermore, this is the first study to show that progressive sweat gland recruitment is a viable physiologic mechanism within localized skin sites.