Maximal oxygen uptake, sweating and tolerance to exercise in the heat.

The purpose of this experiment was to determine if tolerance toexercise in the heat is related to maximal oxygen uptake (max _'02) and sweating.Seven men with max _'02 between 42 and 66 ml/(min-kg) underwent one 2-hr e.xpo-sure at 24°C T_ while working on a bicycle ergometer at _ tel V02 of 28%(5 V'02 = 1.23 lJ'min). In the hot exposures the high capacity subjects had maximalsweat rates of 800 to 1,000 g/{hr" m 2) while the lower capacity men sweated 300to 400 g/{hr" m2). These differences in sweatin_.were__not related to neuromuscu-lar stimuli, V02 {metabolic rate), Tre, aTre, T s, AT s or tolerance time.Tolerance to exercise in the heat was not related to maximal V'02 capacity whenthe subjects worked at the same relative load in spite of large differences insweating. These results question the importance of the rate of sweating for pre-dicting work performance in hot environments. ZUSAMMEN'FASSUNG. Das Ziel dieser Untersuchung war, zu prUfen, ob dieToleranz bei Arbeit in der Hitze in einer Beziehung steht zur ma.ximalen O2-Auf-nahme and Schwitzen. Sieben M'_nner mit V02zwischen 42 66 ml/(min, kg)wurden belastet wRhrend 2 Stunden bei T a 24DC und 3 x 2 Stunden bei 47oc mitArbeit auf dem Fahrrad-Ergometerbei im Mittel yon 28% V02 = 1.23 1/min.W_rend der Hitzebelastung zeigten die leistangsflihigen Personen Schweissekre-• a n yon 80