By Mary Carpenter
SINCE Mary Carpenter’s 2014 post on napping, new health benefits of naps, as well as napping methods and tips, keep popping up for the almost one-third of Americans who partake. But nothing has made a news splash like the recent New York Times editorial, “Work is a False Idol,” by Cassady Rosenblum.
“Lying flat is justice,” Rosenblum quotes Chinese former factory worker Luo Huazhong); and “Rest is not only resistance, it is also reparation,” from Atlanta-based Nap Ministry head Tricia Hersey. Casey Gerald, author of the essay, “The Black Art of Escape,” exhorts: “Miss the moment. Go Mad, go missing, take a nap…”
More than naps alone, these writers advocate opting out of “996”—9am to 9pm, six days a week —careers to choose instead simply working for sustenance. Rosenblum herself opted out—of the “cacophony of the 24-hour news cycle” as an NPR producer—to sit on her parents’ porch in West Virginia.
Before the lying-flatters came a long line of famous nappers, including Winston Churchill, John F. Kennedy and Thomas Edison. Most well known, particularly for his napping technique, is Albert Einstein —who sat after lunch with his heavy wristwatch in one hand, which he dangled over the edge of his chair until the watch fell, and the noise woke him up—nap over.
Among napping tips, the most popular may be consuming a caffeine drink before a 15-minute nap to help avoid “sleep inertia” upon awakening—because caffeine kicks in about 15 minutes after consumption, according to myclevelandclinic. But because caffeine’s effects can last as long as 10 hours, timing the nap for early afternoon may be important for getting a good night’s sleep.
Restorative or replacement naps make up for sleep loss due to poor sleep—but become less useful after a string of sleep-deprived nights, according to Sleep.org. And missing just one hour of sleep can require many nights of restorative sleep to compensate.
The ideal nap length “is long enough to be refreshing but not so long that sleep inertia occurs,” according to the Sleep Foundation, which recommends 10 to 20 minutes as “the ideal length.”
But the length of a nap is “very personal,” according to Chevy Chase Center for Sleep and Wake Disorders Medical Director Helene Emsellem. “For some a five-to-10-minute nap can provide improvement for the next few hours. And a nap in the 20- to 30-minute range can reset you.”
Besides the so-called “recovery” nap, people may take an appetitive nap—“for the enjoyment of napping,” according to the Sleep Foundation. The appetitive nap seems to create less sleep inertia—because the napper is either better accustomed to the timing and to waking up, or is simply less sleep-deprived.
Other nap categories include the prophylactic nap —in preparation for sleep loss; the essential nap—needed during illness, when the immune system requires extra energy to fight infection; and the fulfillment nap —usually for children, to fill their greater sleep needs.
The most oft-touted health benefit of napping is lowered risk of cardiovascular problems. In a Swiss study of nearly 3,500 adults ages 35 to 75 tracked over five years, those who napped once or twice a week were 48 percent less likely than non-nappers to suffer serious heart attack, stroke or heart failure. The length of naps made no difference nor did napping more often than a couple of times a week.
Napping may also increase memory retention—as in the phrase “you should sleep on it”—especially if aligned with the natural sleep cycle. For this reason, nap lengths of 60 minutes that include “slow wave” sleep may be better for cognitive memory processing. And napping for the full sleep cycle of 90 minutes may bolster both memory and creativity.
But even shorter naps can help move information to more permanent storage in cortical areas of the brain from temporary storage in the hippocampus, which in turn clears the hippocampus of recent learning to make room for new information. In a multi-country study, napping resulted in not just “strengthening of rote memories but also the binding of items that were not directly learned together, reorganizing them for flexible use at a later time.”
In addition, naps can decrease the risk of general cognitive dysfunction, strengthen the immune system and even reduce symptoms of sleep disorders, including hypersomnia and insomnia.
For some people, however, naps are unhelpful and disruptive to nighttime sleep. And lengthy or excessive napping may lead to diminished productivity, while sleep inertia following naps can increase the risk of human error. Some research has also linked long naps to higher mortality among older adults.
My own almost-daily, about 15-minute naps started as efforts to do short, mindful meditations along with resting my aching back— lying flat, years before the napping boon. But mine may also be recovery naps, based on the finding that dreaming during short naps can be a sign of sleep deprivation—and because, instead of meditating, I fall asleep so easily I must set an alarm.
Finally, though, my naps may have become “appetitive”—as the Sleep Foundation explains, because “people who enjoy napping sometimes make it a habit.”
—Mary Carpenter regularly reports on topical subjects in health and medicine.