Neuromuscular failure is unlikely to explain the early exercise cessation in hot ambient conditions

Abstract

Baseline, postexercise (20min cycling) and postexhaustion (incremental test) neuromuscular function was assessed in control (24°C) and hot (40°C) conditions. Heat affects the plantar flexors and knee extensors differently, but most of the effects of heat (e.g., M-wave decrement) and fatigue (e.g., voluntary activation and H-reflex decrement) were independent of each other. However, peripheral fatigue of the knee extensors was lower at exhaustion in hot than neutral environment (peak twitch decrement from baseline to exhaustion: -19% vs. -33%, p