A new study suggests that a dose of extra sleep on the weekend may be good medicine for adults who repeatedly stay up too late or wake up too early during the workweek. However, even a night of 10 hours in bed may not be enough to cure the negative effects of chronic sleep restriction.
Results show that neurobehavioral impairments such as increased lapses of attention and delayed reaction times accumulated across a period of 5 days when sleep was restricted to less than 4 hours per night. Behavioral, subjective, and physiological measures of alertness improved significantly after a night of recovery sleep, with larger doses of sleep producing greater gains. Yet some neurobehavioral deficits continued to linger after the maximum recovery dose of 10 hours in bed, during which participants slept for an average of about 9 hours. The study suggests that complete recovery from sustained sleep restriction may require even more sleep during 1 night or multiple nights of extended sleep.
"Recovery of alertness dimensions was remarkably dependent on the duration of the recovery time in bed," said principal investigator David F. Dinges, PhD, director of the Unit for Experimental Psychiatry and chief of the Division of Sleep and Chronobiology at the University of Pennsylvania School of Medicine in Philadelphia. "However, the sleep restriction was severe enough that recovery of alertness was not complete following a single night of extended sleep, indicating a residual sleep debt remained. Lifestyles that involve chronic sleep restriction during the workweek and during days off work may result in continuing buildup of sleep pressure and in an increased likelihood of loss of alertness and increased errors."
The study appears in the August 1 issue of the journal Sleep.