Five-Hour Sleep Restriction for 7 Days Increases Subjective Sleepiness

Abstract

We investigated the effects of a 5-h sleep restriction for 7 d on subjective sleepiness in an ambulatory condition by comparing them with baseline conditions consisting of an 8-h sleep for 7 consecutive days. Subjects were 13 healthy male students (mean age 21.1 yr). Each subject was required to get 8 h of sleep (baseline, from 2300 to 0700) for 7 d, and 5 h of sleep (sleep restriction, from 0100 to 0600) for 7 d in an ambulatory condition. The order of the two sleep schedules was randomly assigned. Subjective sleepiness was assessed by a Visual Analog Scale (VAS) every 3 h at 0900, 1200, 1500, 1800, and 2100 for 7 successive days during each sleep schedule. The VAS score during sleep restriction gradually increased up to the 5th day and then reached a plateau. The patterns of time-course changes in the VAS score were similar to those at baseline. The VAS scores showed a peak at 0900, taking a dip at 1200, and then gradually increasing toward 2100. The mean VAS score of the last three days of the 5-h sleep restriction was significantly higher than that at baseline (p<0.001). A 5-h sleep restriction for 7 d in an ambulatory condition increased subjective sleepiness up to the 5th day and then reached a plateau. The patterns of the time-course changes in sleepiness of 5-h sleep restriction per day did not differ from that at baseline.

Differential Kinetics in Alteration and Recovery of Cognitive Processes from a Chronic Sleep Restriction in Young Healthy Men

“…Under such sleep restriction conditions, we observed that subjects felt sleepy from the 4th day until the last day and this subjective complaint seems to rapidly ceil at a score of 5. These results are in line with those of previous studies (Belenky et al, 2003 ; Van Dongen et al, 2003 ; Kobayashi et al, 2007 ; Lo et al, 2012 ; Philip et al, 2012 ). In parallel, our results demonstrate that a week of severe sleep restriction (4 h of TIB) is both responsible for sustained attention deficits, with a decrease of response speed and an increase in the number of lapses, and executive disorders with an increase in the numbers of errors (“No-Go” trials) while sleepy subjects were still able to perform a sensori-motor coordination task.…”

Sleep: a ‘Wake-up’ Call

“…Sleep disorders may be caused by underlying emotional disorders, that is, anxiety or depression, and sleep disorder may worsen each of them (12). Sleep deprivation leads to a drop in academic performance (7), increases day-time sleepiness (13), leads to early fatigue (5), decreases alertness (14) and increases errors at work. In house officers, it affects divergent and creative thinking (15), decreases surgical dexterity (16), and increases errors in healthcare.…”