Previous sleep studies asked people to count their hours of sleep for an average night, without distinguishing between workdays and days off. People under the age of 65 who slept for five hours or less every night, all week, did not live as long as those who consistently slept seven hours a night. People who slept for fewer than the recommended seven hours each weekday, but caught an extra hour or two on weekends, lived just as long as people who always slept seven hours, the authors reported. People in their late teens and 20s slept on average for seven hours a night during the week but 8.5 hours on days off. This study was not an experiment, Akerstedt emphasized, and these data cannot show that short or long sleep is responsible for higher mortality.

Source: Washington Post May 23, 2018 12:19 UTC