The relevance of age for work in a warm humid climate

Abstract

The present study was designed to study the relevance of age related differences in heat stress response in relation to physical fitness related differences. For this purpose, a test group was selected (age 20-73 years) in which no correlation was present between the subjects fitness level and their age, but in which large variations of both parameters within groups were present. The question whether the effect of age, as observed in other studies, is relevant com-pared to the effect of physical fitness was answered in a negative sense. Though a small age effect may exist, this is only measurable when groups are matched precisely with respect to their physical characteristics. No relevant age effect on heat stress response in body core temperature and heart rate (expressed as percentage of maximal heart rate) is present when comparing age groups with equal average V_O2max. The reduction in individual absolute maximal heart rate with age resulted in lower heart rates for equal work loads in older subjects