Thermal perception in trained and untrained young men

Abstract

Increase in skin and esophageal temperature (Tsk and Tes) enhances autonomic and behavioral thermoregulatory responses with the perception of both temperatures. Endurance training increases autonomic thermoregulatory responses therefore we assessed if the perception of both temperatures was modified with endurance training.MethodsSeven trained (< 3 days of training/week) and six untrained healthy young men underwent measurements of noticeable increase/decrease (± 0.1°C/sec) of skin temperature (warm/cold threshold) at chest by using a thermode (6.25 cm2), and of subjective whole body thermal sensation (visual analogue scale) in normothermia (NT, Tes; 36.6 ± 0.2°C) and hyperthermia (HT, Tes; 37.3 ± 0.1°C, lower legs immersion in 42°C water). Tes, Tsk, and cutaneous vascular conductance (CVC) and sweat rate (SR) at forearm and chest were measured continuously.ResultsIn both groups, cold threshold was decreased and subjective whole body thermal sensation, CVC and SR at both sites were increased in HT compared with NT (P < 0.05), while warm threshold remained unchanged. In NT and HT, cold threshold and subjective whole body thermal sensation were similar in both groups, while warm threshold was lower (more sensitive) in trained than untrained men (P < 0.05).ConclusionsSkin warm perception but not skin cold perception or whole body thermal sensation is more sensitive in trained than untrained men.