MUSCLE AFFERENT STIMULATION INCREASES SWEAT RATE DURING DYNAMIC EXERCISE

Abstract

In warm environmental conditions, short-term dynamic exercise increases sweat rate (SR) without elevating internal temperature. We hypothesized that muscle afferent stimulation contributes to this sweating response. PURPOSE & METHODS To investigate this hypothesis, seven subjects performed 3 min of moderate dynamic exercise (heart rate, HR, of ∼ 130 beats per min) with and without 60 mmHg pressure applied to thigh cuffs on both legs. This perturbation augments muscle metaboreceptor and possibly mechoreceptor stimulation during exercise. HR, mean arterial blood pressure (MAP), and SR on forearm and palm, and internal and skin temperatures were continuously measured. RESULTS Neither internal nor skin temperatures increased during these brief exercise bouts regardless of thigh cuff pressure. The elevation in forearm SR as well as HR and MAP were significantly greater during exercise with cuff inflation than without, while the increase in palm SR was not different between exercise trials.Table: No Caption AvailableCONCLUSION These results suggested that activation of skeletal muscle afferents could modulate sweat rate in non-glabrous skin but not in glabrous skin during dynamic exercise.