Abstract

Eight subjects underwent an exercise training programm (10 days at 75 VO 2 max for 1 h/day at 25 Grad C db/13 Grad C wb) and a heat-acclimation program (10 days at 50 V0 2 max for 1 h/day at 35 Grad db/32 Grad C wb). The rela- tions of chest sweat rate and of forearm blood flow to internal temperature were determined for each subject at a 25 Grad C ambient temperature before training, between training and acclimation, and following acclimation. Trai- ning shifted the vasodilation and sweating thresholds toward lower internal temperatures, and acclimation further lowered these thresholds. All threshold shifts were statistically significant (P<0.05). Training and acclimation both appeared to increase the slope of the sweating relation, but these effects were not statistically significant. Changes in the slope of the blood flow relation were small and inconsistent. Since arm blood flow is higher at any given internal temperature after acclimation, the lower blood flow which ist reported to accompany heat acclimation must result from the lower body tempe- ratures. Verf.-Referat