Mechanisms of Aerobic Performance Impairment With Heat Stress and Dehydration
Abstract
Environmental heat stress can challenge the limits of human cardiovascular and temperature regulation, body fluid balance, and thus aerobic performance. This minireview proposes that the cardiovascular adjustments accompanying high skin temperatures (Tsk), alone or in combination with high core body temperatures (Tc), provide a primary explanation for impaired aerobic exercise performance in warm-hot environments. The independent (Tsk) and combined (Tsk + Tc) effects of hyperthermia reduce maximal oxygen uptake (VO2max), which leads to higher relative exercise intensity and an exponential decline in aerobic performance at any given exercise workload. Greater relative exercise intensity increases cardiovascular strain, which is a prominent mediator of rated perceived exertion. As a consequence, incremental or constant-rate exercise is more difficult to sustain (earlier fatigue) or requires a slowing of self-paced exercise to achieve a similar sensation of effort.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2010
- Accession Number
- ADA540814
Entities
People
- Michael N. Sawka
- Robert W. Kenefick
- Samuel N. Cheuvront
- Scott J. Montain
Organizations
- United States Army Research Institute of Environmental Medicine