Energy balance during moderate exercise at altitude

Abstract

Abstract. The purpose of this study was to determine the effects of chronic hypoxia on heat exchange mechanisms during exercise in acclimatized and unacclimatized subjects at altitude. Core temperature increased by the same increment at the end of exercise in all subjects, whereas mean skin temperature rose in subjects in their own environment and decreased in unacclimatized subjects. The energy balance was calculated by, partitional calorimetry. The body stored heat during entire exercise in each case; radiant plus convective heat loss rate was Iower and evaporative loss rate higher for lowlanders when relocated at altitude than at sea level. Thermoregulatory mechanisms were unaffected at altitude by either relative work load or barometric pressure. However relative part played by heat-dissipating mechanisms was different.