Abstract
The physiological and psychological effects of air temperature and exercise intensity on the human body during physical exercise were investigated by a series of experiments. The effects were measured at six different air temperatures, (i.e., 10℃, 15℃, 20℃, 25℃, 30℃, and 35℃), and at four different exercise intensities, (i.e., rest, 25 W, 50 W, and 75 W). The physical exercise consisted of pedaling a bicycle ergometer at the rate of 50 rpm at 15 minute intervals. The subjects were five healthy women of ages 22 to 23 and they wore sports-wear (0.5 clo). The relative humidity was set at 50%. The mean radiant temperature was equal to the ambient temperature and the air velocity was less than 0.2 m/s. The experiments were carried out in August 1985 and in February 1986. The results were as follows: (1) The effects of both air temperature and exercise intensity are observed on physiological responses of the human body (i.e., skin temperatures, rectal temperature, metabolic rate, heart rate, weight loss, and blood pressure) psychological responses (i.e., thermal sensation vote and comfort vote). (2) The lower the air temperature becomes, the lower the mean skin temperature is. The stronger the exercise intensity becomes, with thermal neutrality, the lower the mean skin temperature is. (3) When the comfortable side votes are obtained, the weighted mean body temperature, which is calculated as weighted the mean skin temperature and the rectal temperature, is set to be in between 36℃ and 37℃. Consequently, the weighted mean body temperature has high correlations with the thermal sensation vote. (4) In view of the exercise intensity the recommended temperature ranges were proposed. The recommended temperature ranges are based on the weighted mean body temperature in thermal neutrality. The recommended temperature ranges are less than 0.4 in relation to skin wettedness. When the heart rate is less than 120 beats/minute, the recommended temperature ranges agree with the ranges in which comfortable side votes are obtained. (5) The comfort zone by ASHRAE SET* is within the previously mentioned temperature ranges in 3 Met. Whereas, the comfort zone by Fanger's Comfort Equation spreads toward the lower end of the above mentioned temperature ranges in 3 Met.
