[Sweating response to abrupt changes in work load].
Changes in sweat rate on the palm and on the general body surface in response to stepwise increases and decreases in work load during exercise on a bicycle ergometer were examined in relation to body temperature and heart rate in six male subjects (three trained and three untrained), in an attempt to evaluate thermal and nonthermal factors responsible for those changes. In all the untrained subjects, a transient, marked increase in palmar sweat rate was observed upon an abrupt increase (and occasionally upon an abrupt decrease) in work, while an increase in sweat rate on the general body surface was also rapid and marked. On the other hand, in all the trained subjects, palmar sweat rate was low and hardly showed a substantial increase in response to an abrupt increase in work load, to which sweating on the general body surface responded slowly by a gradual increase. While sweat rate on the general body surface showed a significant correlation with esophageal temperature and with heart rate, palmar sweat rate was not correlated with esophageal temperature but was significantly correlated with heart rate. Moreover, repeated increases and decreases in work load often led to progressive weakening of palmar sweating due apparently to the development of habituation. The present results suggest that responses of sweating to stepwise changes in work load are not solely dependent upon the thermoregulatory mechanism but are affected considerably by increase and decrease in psychic excitement and/or those in discharges of the sympathetic nervous system accompanying changes in work load.(ABSTRACT TRUNCATED AT 250 WORDS)
D000328:Adult; D001833:Body Temperature Regulation; D006339:Heart Rate; D006801:Humans; D008297:Male; D005082:Physical Exertion; D013546:Sweating