How much sleep is too much?
An occasional, short nap can be restorative and boost your day, evidence shows. Even an occasional long nap after a poor night’s sleep is different from regularly napping for extended periods during the day every day or nearly every day, Gao says.
Excessive napping during the day in older age has been linked to everything from neurodegeneration and diabetes to cardiovascular diseases and all-cause mortality .
An older study in the Journal of the American Geriatrics Society found that women 69 and up who took a nap every day had a 44 percent higher mortality risk, compared with those who didn’t sleep during the day.
Nap 101
Michael V. Vitiello, a professor emeritus in psychiatry and behavioral sciences at the University of Washington, says there is no evidence showing that an occasional nap, even if outside the “sweet spot” and/or for longer than 30 minutes, is harmful. The American Heart Association says a 30-minute snooze is OK, just keep it before 3 p.m.
“The sweet spot for napping is between 1 and 4 p.m., optimally seven to eight hours after waking up. This aligns with the body’s natural circadian dip in alertness,” Vitiello says.
Regular, short naps in the midafternoon are not harmful and may provide some benefits to daytime functioning by increasing energy and relieving sleepiness. But regular long naps, particularly those taken in the morning, are linked with increased mortality risk. Long naps may be indicators of underlying disease.
“We don’t fully understand why morning naps are ‘harmful,’ ” Vitiello says. “Likely they are not harmful in and of themselves, especially if infrequent.”
However, regular morning napping, particularly when the nap is long, may be a signal of an underlying disease, he adds.
After a rough night, it is OK to take a brief nap. What’s concerning is regularly experiencing rough nights and repeatedly having to catch up on sleep during the day, which could indicate some underlying sleep disorders or medical issues, Gao says.
She called for more interventional or experimental studies that can tell us whether changing napping patterns will influence health. A lot of research on the topic is correlational, meaning that it simply shows a link between two things, not whether one causes the other.
If you feel that napping improves how you feel during the day, go ahead and nap at the same time of day for under 30 minutes.
“Individuals who nap otherwise ought to consider changing their napping patterns accordingly,” Vitiello says, as well as getting evaluated for sleep problems or an underlying disease that might be causing daytime sleepiness.