FATIGUE REDUCES INSULATION AGAINST THE COLD
Young, A. J., Castellani, J. W., Kain, J. E., Rouse, A., & Sawka, M. N. (1999). Thermoregulation in the cold after exercise. Medicine and Science in Sports and Exercise, 31(5), Supplement abstract 896.
This study examined whether acute exercise would impair the body's ability to maintain thermal balance during subsequent cold exposure. Men (N = 10) sat for two hours in cold air (5 degrees Celsius) following either a 60-minute cycle exercise at 55% VO2max or passive heating (sitting in water at 38 degrees Celsius) to a core temperature that matched that attained by the exercise condition.
Shivering responses to the cold were not affected by fatigue. However, heat is lost more readily from the periphery in fatigued states.
Implication. When exercise precedes cold exposure, individuals may be threatened with excessive cooling unless clothing adjustments or other behavioral strategies are undertaken to offset the reduced insulation.