Abstract
The relationship between increase in rectal temperature and body build during submaximalwork was studied in 8 Japanese males.After resting at 28°C with 50% relative humidity for30min, subjects worked on a bicycle ergometer at load of 450kgm/min with pedaling frequency50rpm for 61min at 28°C or 45°C with 50% relative humidity.Rectal temperature, oxygenuptake and heart rate were measured at rest and during work.Relative work loads wereobtained from prediction of maximal oxygen uptake.Body weight, stature, skinfold thicknessand body density were measured.Body surface area, body fat % and mean skinfold thicknesswere caiuculated by prediction equations.The correlation coefficients between increase in rectal temperature and body build at 45°Cwere larger than those at 28°C.In the conditicn of 45°C, body surface area-to-mass ratio wascorrelated significantly with increase in rectal temperature, whereas the relationship was notsignificant at 28°C.In the condition of 28°C, sigmificant relationship between relative work loadand increase in rectal temperature was found.Body suriace area-to-mass ratio, which meansrelative heat exchange between human body and environment, affects the change in rectaltemperature at high ambient temperature.
