I have a confession: I nap. Most days, after lunch, you will find me snoozing. I used to keep quiet about it. Other countries have strong napping traditions, but here in the U.S. it is often equated with laziness. In 2019 a U.S. federal agency even announced a ban on sleeping in government buildings.
I'm going public about my nap habit now because, despite what bureaucrats may think, sleep scientists are increasingly clear about the power of the nap. That shift is part of the relatively recent recognition that the quality and duration of sleep are public health issues, says physiologist Marta Garaulet of the University of Murcia in Spain.
For a time, research was both for and against napping. Many studies showed mood and cognition benefits from midday rest, yet others found links to poor health, especially in older adults. That left some experts hesitant to “prescribe” naps. More recent research, though, has clarified that different types of naps have different effects. A number of scientists now think the sweet spot is about 20 to 30 minutes.
The urge to nap is governed by two physiological processes. One is called homeostatic sleep pressure (HSP), and it builds the longer you are awake. The other involves daily circadian rhythms, which leave everyone a little sleepy in the afternoon. Some people, like me, are habitual nappers even when we get adequate sleep at night. Others can't nap unless they are severely sleep-deprived. Genes, such as those that underlie HSP, drive much of the difference.