THE EFFECT OF ONE NIGHTS SLEEP-DEPRIVATION ON TEMPERATURE, MOOD, AND PHYSICAL PERFORMANCE IN SUBJECTS WITH DIFFERENT AMOUNTS OF HABITUAL PHYSICAL-ACTIVITY

Eleven healthy males were studied twice. On one occasion (control, C), they slept (night 1) and then underwent a battery of tests at 4h inte rvals from 06:00 day 1 to 02:00 day 2; then, after a normal sleep (nig ht 2), they were tested from 10:00 to 22:00 on day 2. On the second oc casion (sleep deprivation, SD), the subjects remained awake during nig ht 1. Each battery of tests consisted of measurements of tympanic memb rane temperature, profile of mood states (POMS), muscle strength, self -chosen work rate (SCWR), perceived exertion, and heart rate (HR) whil e exercising on a stationary cycle ergometer. Subjects also kept a dia ry of their activities during the two days and answered a questionnair e about their habitual physical activity. Results showed a significant negative effect of sleep deprivation on most mood states on day 1, bu t no effect on the other variables. By day 2, mood had tended to recov er, though muscle strength tended to be worse in both control and slee p-deprivation experiments. There was also a more general tendency for negative effects to be present at the end of day 1 (02:00) or at the b eginning of day 2 (10:00). There was limited support for the view that subjects who were habitually more active showed less negative effects after sleep deprivation and responded less adversely to the poor slee p achieved on the university premises (night 2). These results stress the considerable interindividual variation in the responses to sleep l oss and, therefore, the difficulty associated with giving general advi ce to individuals about work or training capability after sleep loss.