You're right to be confused. Even as a recent study linked napping to higher mortality, companies and colleges across the U.S. are installing nap rooms to boost productivity. Truly, it would be a dream to get some napping consensus.
But whether or not napping is right for you depends. “First of all, it’s important to ask yourself why you’re taking the nap,” says Dr. Sara Mednick, a psychologist at the University of California, Riverside and author of Take a Nap! Change Your Life. If you’re spending a big chunk of your day feeling sleepy and out of sorts, then your desire to snooze may be driven by stress, insomnia, sleep apnea or a hundred other slumber-disrupting health conditions, Mednick says.
“Daytime napping is an early indicator of underlying ill health,” adds Yue Leng, a University of Cambridge sleep researcher and coauthor of the study linking naps to higher mortality rates. Like Mednick, Leng suggests daytime drowsiness is likely a symptom of other health issues, not their cause.
Put simply, blaming naps for higher mortality rates is like blaming your doctor for heart disease; you’re more likely to see a doc if you have heart issues, but that doesn’t mean she’s to blame.
MORE: The Power of Sleep
Actually, naps are good for most people, Mednick says. Her research shows a nap—defined as daytime sleeping that lasts between 15 and 90 minutes—can improve brain functions ranging from memory to focus and creativity. “For some people, naps are as restorative as a whole night of sleep,” she adds. More research shows a quick nap can lower stress and recharge your willpower. And napping has also been linked to lower rates of cardiovascular disease and inflammation.
Illustration by Peter Oumanski for TIME
But all of these benefits depend on you getting a good night of sleep to begin with, Mednick stresses. Also, not everyone is a good napper. “Some people wake up from naps feeling like crap,” she says.
Genetics could explain why some people are nappers and some aren’t. But regardless of the explanation, there’s clearly a difference between the two groups. “People who aren’t habitual nappers tend to fall into very deep sleep during naps, and waking up from that leaves them feeling groggy,” Mednick explains. On the other hand, natural nappers—you know who you are—don’t plunge into deep slumber during their daytime snoozes, Mednick says. This allows them to wake up from naps feeling energized and alert, not discombobulated.
For natural nappers, she says it’s “incredibly important” that you do catch your daytime ZZZs. “These people—and they probably account for about 40% of the population—tend to do really poorly if they don’t nap,” she explains. Without their much needed daytime shuteye, habitual nappers often reach for energy drinks, caffeine or other stimulants that perk them up but don’t recharge their cognitive batteries the way a short, healthy snooze would.
“For these people, skipping their nap is a huge productivity killer,” Mednick says, and that's a compelling reason for employers and universities to provide nap spaces for employees and students.
While the length of an ideal siesta varies from person to person, 20 to 30 minutes is plenty for most. But up to 90 minutes—about the length of one full sleep cycle—could also be beneficial, Mednick says. She recommends trying different nap lengths to find the one that leaves you feeling the most refreshed.
If you’ve never been a napper but want to cash in on napping’s brain and health benefits, Mednick says you may be able to teach yourself to nap. The trick is to keep your daytime shuteye very short—no more than 15 minutes at first. This will prevent your brain and body from slipping into the deeper levels of slumber that leave you feeling foggy upon waking, she adds.
But if you're just not a born napper, don't sweat it. “Everyone’s different," Mednick says. "If you feel good, whatever you’re doing is fine.”