NEW YORK – If you’re one of the hundreds of million people with a sleep problem, there’s a good chance that a sleep myth or two may be keeping you up at night—or leaving you exhausted during the day.
1. Many people are “short sleepers”
Fact: If you genuinely require less than 6 hours of sleep a night, you’re a rarity. A just-discovered genetic mutation does enable some people to function okay on 20 to 25% less sleep than average, but—here’s the catch—researchers estimate that fewer than 1% of people have the trait.
2. Napping only makes you more tired
Fact: Some people swear that quick naps make them sleepier, but a snooze that’s less than 20 minutes should perk most of us up. “Just 10 to 20 minutes is all you need to get the benefits of napping, such as alertness, improved performance, and better mood,” says Kimberly A. Cote, PhD, a sleep researcher at Brock University in Ontario. Here’s why: During sleep, your brain produces different kinds of waves, which correspond to how deeply you sleep. After about 20 minutes, the sleeping brain may move into what’s called slow-wave sleep, which is the deepest phase of sleep. If you nap too long, you may feel groggy and disoriented upon awakening instead of refreshed because long naps are more likely to contain deep slow-wave sleep.
3. Exercise too close to bed keeps you up
Fact: That’s not true for everyone. In fact, research shows that even vigorous exercise right before bedtime doesn’t cause trouble sleeping for many people (and in some cases it may help). This is good news if your busy schedule gives you a short window of time after work to squeeze in some activity. Even people who have trouble sleeping can probably exercise about an hour before bed without problems. “But we don’t have hard data, so people really have to do their own testing,” says Michael Perlis, PhD, director of the University of Pennsylvania Behavioral Sleep Medicine Program.
4. It’s normal to nod off during a meeting
act: It’s normal to feel slightly less energetic in the afternoon because of your body’s natural circadian rhythms. But you shouldn’t feel like your head’s about to droop while your group VP is giving a 4 pm presentation or when your preschooler is explaining why Superman is better than Batman.
If your eyelids feel heavy, you’re too tired, says William C. Dement, MD, PhD, the Stanford University scientist known as the father of sleep medicine. In fact, if you feel tired all the time, you may be running a significant “sleep debt”—the total hours of sleep you’ve lost, one sleep-deprived night after another
5. Go to sleep earlier if you have insomnia
Fact: Step away from the bed. If you suffer from true insomnia, this could make your tossing and turning much worse, says Cote. Blame it on something called the sleep homeostat. A hardwired system controlled by brain chemicals, it’s not unlike your appetite. The longer you go between meals and the more active you are, the hungrier you become. Likewise, your homeostat builds up a hunger for sleep based on how long you’ve been awake and how active you’ve been. The more sleep hungry you are, the faster you nod off and the more soundly you doze. But just as you’re not eager for a big meal at night if you pig out all day or snack too close to dinner, you’re not going to feel tired if you go to bed earlier or nap.
6. Skipping a little sleep isn’t that bad
Fact: Missing even 90 minutes of sleep for just 1 night can reduce your daytime alertness by as much as 32%. That’s enough to impair your memory, your thinking ability, and your safety on the job and on the road. One Australian study found that volunteers who stayed awake just 6 hours past their normal bedtime for a single day performed as poorly on tests gauging attentiveness and reaction time as those who were legally drunk. The National Sleep Foundation’s 2009 poll showed that as many as 1.9 million drivers have had a car crash or a near miss due to drowsiness in the past year.
7. Just catch up on sleep on the weekend
Fact: Unless you have insomnia, it’s theoretically possible to make up for some lost sleep by dozing longer on the weekend. But it’s not realistic. With kids’ birthday parties, sports practices, and all those inevitable weekend errands, chances are you won’t really be able to make up for the sleep you missed, says Dement. You’ll end up finishing the week in the red, with an ever-bigger sleep debt.
8. It doesn’t matter when you go to sleep
Fact: Night owls are nearly 3 times more likely to experience symptoms of depression than early birds, one study found—even when they got the same total amount of sleep. Experts aren’t sure exactly why, but there may be an optimal time within the 24-hour clock to fall asleep and wake up.
9. You have to be in bad shape to take sleeping pills
Fact: Actually, sleeping pills are most helpful if you take them before insomnia becomes chronic, says Carl E. Hunt, MD, director of the National Institutes of Health National Center on Sleep Disorders Research. They can help correct your off-kilter sleep homeostat. Today’s popular pills like Ambien and Sonata, unlike older versions, help you drift off to sleep within minutes and stay asleep, thus breaking the cycle of sleeplessness and anxiety that can turn a few nights of insomnia into chronic sleeplessness.