Interconnections between thermal perception and exercise capacity in the heat.

Some models of exercise regulation suggest that exercise performance, rather than being solely limited by the attainment of fatigue in one or more physiological systems, is modulated by psychological factors. Extrapolating from such models, exercise capacity and voluntary performance during exercise in hot environments may be governed by a complex interplay between the physiological effects of hyperthermia along with psychological input stemming from the conscious perception of the thermal environment. Evidence is emerging for a neuroanatomical basis for peripheral and central thermal receptors to elicit both a distinct physiological response such as shivering or sweating along with being mapped into an overall subjective sensation of homeostasis. Experimental evidence supporting this interactivity includes the demonstration that physiological manipulations, such as an increased fitness, appear to confer an attenuation of thermal discomfort during whole-body exercise despite similar levels of physiological strain. At the same time, psychological interventions have proven effective in decreasing perceived thermal strain and extending exercise performance in hot environments. The purpose of this review was to survey the potential interactions between thermal perception and exercise performance in the heat.