Extra sleep on weekends isn’t a cure-all for lost sleep during the week
Sleeping in on weekends may help you feel more rested after not getting enough sleep during the workweek, but it may not reverse the effects of sleep loss on your attention span, according to a small study in the American Journal of Physiology-Endocrinology and Metabolism.
Studies have consistently shown that lack of sleep can cause problems other than daytime fatigue, such as increased inflammation (believed to play a role in heart attack and stroke) and abnormal blood sugar levels (the defining characteristic of diabetes), according to the American Physiological Society.
But whether “catching up” on one’s sleep—something that Americans commonly attempt to do on weekends—can reverse the ill effects of missed sleep isn’t well known. Researchers sought to answer that question in this study, looking specifically at the relationship between poor sleep, chemical changes in the body and alertness.
About the study
The study involved 30 adults between the ages of 18 and 34 who were healthy and free from sleep disorders. All spent 13 nights in a bedroom-like lab setting.
For the first four nights, people were allowed to sleep eight hours (a healthy amount of sleep, according to the study). The next six nights, researchers woke the people up after six hours of sleep (restricted sleep). For the final three nights, people were allowed to sleep for 10 hours (recovery sleep).
Brain waves were monitored during sleep, and participants underwent a variety of tests throughout the study, including blood tests that measured interleukin-6 (a marker of inflammation) and cortisol (a hormone released during periods of stress).
Finally, researchers measured attentiveness by having participants take a test in which they pressed a button whenever a dot appeared on a screen.
The study found that interleukin-6 levels rose sharply after restricted sleep. However, that effect was reversed after two nights of recovery sleep.
The relatively mild sleep restriction in this study didn’t raise cortisol levels, but the authors noted that previous studies found that cortisol levels increased after more severe limits on sleep.
Cortisol levels did drop during recovery sleep, however, suggesting that sleep “may serve as an ‘antistress’ antidote,” the authors wrote.
Notably, the participants’ scores on the attention test, which fell along with fewer hours of sleep, did not get better after two nights—a typical weekend—of recovery sleep. This suggested that more than a weekend of extra sleep may be needed to make up for not getting enough sleep during the week.
|The take-home message|
|Many Americans cut back on sleep during the workweek, with plans to make up for it by sleeping more on their days off.
That may not be a safe tactic, according to the study’s findings.
Those who may particularly want to rethink it are people whose job requires them to be alert so they can care safely for others or for themselves, the authors suggested.