Thermoregulatory Responses in Cross-country Skiers a Field Study

Outdoors activities, such as cross-country skiing, may expose the human body to severe thermal stress during training and competitive events in the winter season. Cooling affects all aspects of muscular performance (1), and cold has a profound effect on the functional properties of skeletal muscle. When exercise intensity is high enough to maintain core temperature, but skin cooling is still present, a change in muscle temperature is also likely, and this may reduce mechanical efficiency and thus increase the total energy cost (2, 3). The physiological alterations from cold exposure may lead to earlier onset of fatigue, producing negative effects on endurance time to exhaustion (4, 5).