The Sweet Science of Dozing

The healthy benefits of midday napping.

3 min read
One of the most important pieces of equipment in the Boston University office of psychologist William Anthony, Ph.D., is a long beige couch. But Anthony doesn't use it for counseling sessions. He takes naps there.

Anthony campaigns tirelessly (except in the early afternoon) to promote the snooze. A short nap, he says, increases productivity, sharpens the senses, and lifts the spirit. "It's what your mother told you when you were a cranky toddler: Go take a nap," he says. "It works the same way with adults."

Anthony's work as Director of BU's Center for Psychological Rehabilitation doesn't involve sleep research. But extolling the virtues of napping in books and on the Internet is a fun sideline for Anthony, who relies as much on silly anecdotes as scientific studies to make his case. Sleep studies, he says, put him to sleep.

But the scientific data documenting the benefits of napping -- at least for some people -- continue to mount. Some of the most recent research suggests that a bad night's sleep can stress the body as well as the mind.

One such study, reported in the October 23, 1999 issue of The Lancet, suggests that missing sleep throws the body's metabolism off kilter. Scientists at the University of Chicago studied physical changes in 11 young men who slept four hours per night for six nights in a row. They found that sleep deprivation seemed to trigger a diabetes-like condition, harmed hormone production, and interfered with the ability to use carbohydrates.

But does a nap in the afternoon make up for midnight tossing and turning?

Yes, according to some studies, including those conducted at the Henry Ford Hospital's Sleep Disorders and Research Center in Detroit. Napping is "clearly beneficial to someone who is a normal sleeper but who is getting insufficient sleep at night," says center director Timothy Roehrs, Ph.D. "We don't understand the underlying neurobiology, but sleep time is cumulative."

Roehrs says his group compared the alertness of people who slept eight hours a night to that of people who slept less but took a nap during the day. Both groups were equivalent, he says.

His group has also found benefits in the "prophylactic" nap for people who have to stay up late. "It protected them from sleepiness," he says. "A two-hour or a four-hour nap, before they have to be up all night, does provide additional alertness the next day." Research conducted by NASA produced similar results.

Naps are clearly useful for some people, including shift workers, students, and anyone doing long-haul work, such as pilots on transcontinental runs.

But afternoon sleep won't benefit everyone, especially people suffering from insomnia or depression, says Michael Perlis, Ph.D., Assistant Director of the University of Rochester Sleep Research Laboratory. "In the case of the former, napping may worsen nocturnal sleep in patients with insomnia," he says. "As for the latter, napping may increase depressive symptoms."

Sleep researchers agree that anyone who wants to benefit from a nap should make sure not to lie down too close to bedtime or sleep for more than 90 minutes. Doing so can throw off the circadian rhythm -- the body's internal clock.

Anthony's personal rhythm now includes his afternoon nap. He falls asleep easily -- despite the loud rattle of the Boston's "T" trolley, which runs right past his office -- and wakes up automatically after 20 minutes.

Along with his wife, Camille, Anthony has written two lighthearted "Art of Napping" books, sells napping equipment on a web site, and makes the rounds of the morning talk shows.

His latest campaign is to promote workplace napping. On his web site he sells little signs to hang on your office doorknob that read "Working Nap in Progress."

"Most Americans are sleep deprived," he says. "They're having accidents, they're not being as productive as they could be, and they're being interpersonal dolts -- all because they are sleepy."

In his book, he offers tips on how to sleep at work, something most employers discourage. But Anthony profiles the Pittsburgh office of Delloite Consulting and a Connecticut metals distributor, which offer workers a nap room.

The bottom line, he says: "There is something to be said for getting horizontal."