PHILADELPHIA, Aug. 4 (UPI) -- A "recovery night" of 10 hours of sleep is not enough to make up completely for chronic sleep loss, U.S. researchers say.
Researchers at University of Pennsylvania School of Medicine in Philadelphia find more hours of "make-up" sleep produced greater gains in alertness and fewer errors and suggested extending the length of recovery night, or having several nights of extended sleep.
The study, published in the journal Sleep, indicates performance and alertness deteriorated profoundly when nightly sleep deficits were followed by a night with 2 hours or less of sleep.
"This highlights the importance of avoiding all-night sleep deprivation following a period of restricted sleep," principal investigator David Dinges says in a statement.
Dinges and colleagues tested neurobehavior during wakefulness for 159 healthy adults with a mean age of 30. After sleeping 10 hours for two nights, 142 participants were randomized to 4 hours sleep for five nights and then to one of six doses -- ranging from 0 to 10 hours -- of recovery sleep. The control group -- the other 17 participants -- slept 10 hours daily.