Five healthy male volunteers performed 30 min treadmill running at about 60 per cent of maximal oxygen uptake under a cold (6±0.9℃, mean±SD), a mild (18.6±1.3℃) and a hot (32.9±1.1℃) environmental temperature, respectively.
　It was observed as follows: Mean heart rate during exercise was 156.4±10.8 beats per min under a hot, but was 140.9±8.8 in a cold, and 140.9±13.9 beats per min in a mild environmental temperature. There were no significant differences in the oxygen uptake during exercise in these three experimental conditions. Diastolic blood pressure immediately after running under cold and mild temperatures remained unchanged from the pre-exercise levels but the pre-exercise value of 74.0 mmHg dropped to 29.2 mmHg in a hot temperature. There was no difference in elevation of post-exercise systolic pressure under three experimental conditions.
　Plasma angiotensin II aldosterone, WBC counts, and blood glucose levels immediately after running in a hot temperature increased markedly but no change in electrolytes in blood was observed. Serum osmotic pressure after exercise in a hot environment was slightly raised but was no significant statistically. Urine volume, sodium excretion in urine and glomerular filtration rate (creatinine clearance: Ccr) after exercise under a hot environmental temperature were found decreased significantly.

DESCENTE SPORTS SCIENCE Vol.2/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE