Are Naps Good or Bad
There are two kinds of people in this world: happy nappers who, like me, wake up revived from a short afternoon snooze, ready to tackle the remainder of the day with fresh and annoying vigor; and napping naysayers like my wife who can’t stand naps and think people like me are just lazy asses or sleep freaks.
So who has it right?
The ambiguous science on naps could fuel a lifetime of marital spats. Whether naps are good or bad for the body and mind depends on a bunch of things, including age, genes, physical health and mental well-being, nighttime sleep patterns, how long naps last, and, well… before you nod off, let’s take a serious look at the science of napping and its many nuances.
A good thing… for some people
There is evidence that afternoon naps can improve cognitive ability, boost recall after cramming for a test, tamp down impulsivity and frustration, and more generally enhance overall mental performance. But you have to add up a lot of small, mostly inconclusive studies to arrive at these tentative conclusions.
And even then, napping is not for everyone.
Napping varies notably by country and culture, with the siesta common in many countries while in the Western world, particularly the United States, afternoon somnolence is chided as lackadaisically unproductive. However, about one-third of U.S. adults nap, a figure that’s consistent until around age 80, when it jumps to half or more.
Across age groups, men nap more than women, as many women are well aware.
“I consider napping to be a good thing, but it needs to be taken in the context of the person and his or her own sleep cycles and body,” says Charlene Gamaldo, MD, medical director of Johns Hopkins Sleep Disorders Center.
A chief complaint of non-nappers is the dreaded post-nap lethargy, a phenomenon scientists call “sleep inertia.” It’s not clear why some people suffer it and others do not, but there’s a popular theory that goes like this: When they nap, some people tend to stay in the early, light stages of sleep that are easy to snap out of. That’s me, for sure. Others — and my wife fits this bill — conk out totally, falling into a deep slumber called slow-wave sleep, which in a full sleep cycle is normally followed by gradual stages of lighter sleep prior to awakening. The differences may be linked to situations and experiences — how tired you are, basically — but genetics likely play a role. The effects can either make or break the rest of an afternoon.
Watch for a “vicious cycle”
New research confirms a view that sleep experts generally agree on: Too much napping is generally not a good thing, yet it’s not clear why.
Excessive napping in older people predicts a higher risk of developing Alzheimer’s disease, and people diagnosed with Alzheimer’s nap more as they age, the new study finds. It’s a “vicious cycle,” says Peng Li, PhD, a researcher in the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital and first author of the study paper, published this month in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
The research was based on napping data collected by a wrist-worn device on 1,000 people, average age 81, over a 14-year period.
“Older adults tended to nap longer and more frequently as they grew even older, and these changes sped up dramatically with the progression of Alzheimer’s dementia,” Li explains in an email. “Longer and more frequent daytime naps in cognitively normal adults also predicted an elevated risk of developing Alzheimer’s dementia in the future. We also found that longer, more frequent daytime naps were associated with worse cognitive performance in the following year, and worse cognitive performance predicted even longer, more frequent daytime naps in the subsequent year.”
The study does not reveal any firm conclusions about cause and effect, however. It’s possible that daytime naps disrupt nighttime sleep patterns, or that poor sleep at night — sometimes a product of malfunctioning body clocks — leads to daytime napping, Li explains. Napping could also be a sign of some other underlying issue that causes cognitive decline and dementia.
Whatever your age, if you nap regularly and it seems to work for you — meaning you’re alert afterward and generally in good health overall — then there may be little harm in sticking with it.
But aim for consistency, Li says. If your napping is erratic or the timing and duration change significantly, Li advises keeping an eye on your health and well-being, and consider talking to a primary care provider. Irregular nap times may be worse for your sleep-wake cycle, compared to a routine schedule, he says.
You might experiment with some nap management, too.
“If you need to be alert right after waking up (for example, if you’re catching a few extra minutes of sleep during your lunch break), so-called power naps of 10 to 30 minutes are recommended,” write Swedish psychologists John Axelsson and Tina Sundelin in The Conversation. “Longer naps may cause some initial drowsiness — though they keep sleepiness at bay longer. But drinking coffee directly before a nap may help you wake up without feeling drowsy while also boosting your alertness.”
Keep it short
Most sleep experts advise keeping naps short — setting an alarm if necessary — both to avoid grogginess and so you don’t ruin nighttime sleep. But here’s another reason: Long naps have been linked by multiple studies to poor health, including a notably higher risk of stroke.
A 2020 study in the journal Sleep Medicine found that people who typically nap for more than an hour have a 34% higher risk of cardiovascular disease and a 30% higher risk of premature death by any cause, compared to folks who don’t nap. Naps of any duration brought a 19% higher risk of death — one sign that the science of napping remains as fuzzy as your head after a long nap. However, short naps, especially less than 45 minutes, were not found to increase cardiovascular disease risk.
“If you want to take a siesta, our study indicates it’s safest to keep it under an hour,” said study team member Zhe Pan, MD, of Guangzhou Medical University in China. “For those of us not in the habit of a daytime slumber, there is no convincing evidence to start.”
Okay, it’s naptime. When I wake up, refreshed and clearheaded, I’ll decide whether to send this article to my wife or not.