Only about a third of American adults nap, according to a 2009 Pew Research Center study -- mostly men over age 50. Women nap less than men, although they suffer more daytime sleepiness, in part because of their roles as caregivers to the young and old. Home health aides -- a largely female occupation -- topped 2012's most sleep-deprived jobs, in a list issued by Sleepy's, a mattress company, which used U.S. Centers for Disease Control and Prevention data. (Next came lawyers, police officers, doctors and paramedics, social workers, and computer programmers.)
"Do the best you can," says Karl Doghramji, director of the Jefferson Sleep Disorders Center at Jefferson University Hospital in Philadelphia. "If you're sleepy and you need to nap, taking one that's less than optimal is better than no nap at all."
But to get the most from your rest, try these nap tactics:
Customize your start and stop times
There's no one-size-fits-all ideal nap. For most people, there's a window of opportunity around 1 p.m. to 2 p.m., when humans experience a dip in their circadian rhythm, says Doghramji, causing energy to flag. This roughly corresponds to a dip in the body's internal clock 12 hours earlier, or between midnight and dawn, when we sleep most deeply. Almost everyone experiences this post-lunch dip -- regardless of what they ate at midday.
The ideal nap length to reduce sleepiness and improve general thinking skills (like boosting alertness), with the fewest side effects, is ten minutes, according to a 2006 Australian study in the journal Sleep. In these so-called "power naps," you wake up before transitioning to deep sleep. A five-minute nap, in contrast, gave little benefit.
But longer naps can work, too. "A 30- to 45-minute nap hits the magic number for most sleep-deprived people," Doghramji says.
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What helps
- Consider what your brain might need from sleep. Thirty-minute naps tend to bring on a deeper sleep state that's good for remembering things, research has shown -- smart for students studying, for example -- but can be harder to snap out of. A really long shut-eye -- 90 minutes or so -- is thought to boost creative thinking because you rotate through an entire sleep cycle. Ninety-minute naps have also been found to enhance calm.
- Factor in how well you're sleeping at night. To figure a good nap length for yourself, experiment. "Start with a half-hour nap -- that's the amount many studies of shift workers are based on," Doghramji says. "If it helps, stick to it or even try expanding the nap. But if it disrupts your night sleep, cut back." If you have trouble with sleeplessness at night, limit naps to no more than ten minutes. Or avoid napping altogether, Doghramji says. Daytime sleep will further interfere with your already-impaired ability to fall asleep and stay asleep at bedtime.
- Don't start too late. Unless you're working a night shift or partying late, you don't want to nap after 3 p.m., suggests the National Sleep Foundation, or you may pay for it with troubled night sleep.
- Set an alarm to wake you up. Use your mobile phone alarm. Or consider one of the many sleep-tracking gadgets, like Sleeptracker, a watch containing a tiny motion sensor that reads when you're sleeping restlessly, which can signal a shift to a lighter sleep phase. The idea is that this awakens you at an optimal time, when you're less apt to be groggy.
Drink some coffee first
Caffeine is a stimulant that helps you stay awake -- which is why many people lean on coffee and energy drinks to plough through a busy day. Unfortunately, caffeine is less effective at keeping you awake than a good old nap, research shows.
There is a way to use caffeine to enhance the benefit of napping, however. Because caffeine takes about 15 to 30 minutes to have an effect after it's swallowed, some sleep experts suggest drinking a cup of coffee or another caffeinated beverage right before you nap. That way, when you awaken in 10 or 15 minutes, the caffeine will kick in and give you an energy jolt on top of the restorative effects of sleep.
What helps:
- Use a "caffeine nap" on long drives, too. This finding is based on British comparative research that found the caffeine-plus-nap combo was more effective for helping sleepy drivers than either using caffeine alone, cold air, the radio, getting more nighttime sleep, taking a placebo, or using rest alone. The National Sleep Foundation recommends that sleepy drivers pull over in a safe spot, drink a caffeinated drink, and sleep for 20 minutes or so before driving again.
- Quit caffeine for the rest of the day. Continuing to guzzle black coffee and power drinks will only interfere with night sleep.
