Friday, 25 November 2011
9 Sleep Myths That Make You Tired
If you're one of the 60 to 70 million Americans 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. Before you invest in a new $1,500 mattress or spend a couple of nights wired with electrodes in a sleep lab, see if you can trace your sleep troubles to one of these widely believed myths. Then try our tips for better sleep every night.
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.
Energy fix: Two likely signs you're among the lucky short-sleeping crowd: You wake up regularly without an alarm clock, and at the same time every day—weekdays, weekends, vacations—says Emory University sleep expert David Schulman, MD. "But most of us need 7 to 8 hours of sleep to stay healthy."
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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.
When you nap also matters. "A power nap should be early in the day so it doesn't interfere with your ability to fall asleep at bedtime," says David Neubauer, MD, associate director of the Johns Hopkins Sleep Disorders Center. Most people's inner body clocks trigger drowsiness somewhere between 1 and 4 PM.
Energy fix: To make naps a daily ritual, doze off faster by using something you associate with sleep (a favorite pillow or lavender eye mask). Also, nap in a comfortable chair or couch instead of your bed to avoid the temptation to doze for too long, so you don't wake up with a sleep hangover.
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.
Energy fix: Experiment. If you exercise at night and suspect that your workout may be keeping you up, reschedule it for earlier in the day for several days to see whether you sleep better. Keeping a sleep diary for those days—noting when you exercise and how well you sleep—can help. If you find you do sleep better when you exercise earlier, make the switch permanent.
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4. It's normal to nod off during a meeting
Fact: 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 during the day, you may be running a significant "sleep debt"—the total hours of sleep you've lost, one sleep-deprived night after another. If you need 8 hours of sleep and get only 7, after a week you've lost the equivalent of almost one night's sleep. That's your sleep debt. After losing only the equivalent of one night's sleep over the course of a week, your body will respond as if you'd pulled an all-nighter: You may experience waves of extreme fatigue; itchy, burning eyes; mood swings; inability to focus; and even hunger as your body tries to find a way ("Aha! Chocolate-covered pretzels!") to grasp on to energy. Sleep debt is linked with chronic, serious health issues like high blood pressure and diabetes.
Energy fix: If your sleep is interrupted once in a while, one good night's sleep will help you feel refreshed. Chronic problems—stress, a snoring spouse, the snuggling pet—will require specific solutions (a visit to the doctor, a bed in the hallway for Spike). But if you're cheating yourself of sleep time "to get things done," or if you just don't realize how much sleep you need, you have to adjust your bedtime and hit the hay earlier (try this tip to get more sleep).
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. When you have insomnia, experts recommend that you let your sleep homeostat adjust itself naturally, without trying to compensate with different bedtimes and catnaps.
Energy fix: Go to bed an hour later than usual (to make yourself more tired). If you feel anxious about falling asleep, get up and leave the bedroom. Try reading or some other low-key activity. Two other tips that can help bring on natural sleep: Dunk in a warm bath before bed. It temporarily spikes your body temperature, but lying down afterward makes it drop because your muscles relax and produce less heat. Sleep tends to follow a steep decline in body temperature. Also, exercise during the day. Research shows that a 30- to 45-minute bout helps insomniacs enjoy better and somewhat longer sleep.
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6. Skipping a little sleep isn't that horrible
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.
What's worse, sleep deprivation also impairs your ability to recognize that you're not running on all cylinders. In other words, you really shouldn't be operating heavy machinery (or much else), but you don't realize it. "The ability to judge how well you're doing is probably one of the first things to go when you don't get enough sleep," says Cote. "That's why you need to take preventive measures."
Energy fix: If you miss several hours of sleep one night, consider calling in sick the next day or ask if you can work from home. (That way, you won't have to drive.) If you find yourself nodding off at your desk, take a brisk walk up and down the stairs or hall. Exercise helps you snap to, in part because the accompanying rise in body temperature appears to boost alertness for a time. If possible, set aside part of your lunch hour for a nap. Remember to set an alarm, or ask a buddy to wake you.
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.
Energy fix: Don't regularly skimp on weekday sleep with the expectation you'll bounce back over the weekend. If you do happen to rack up an occasional sleep debt during the workweek, try to sleep later on the weekend or take a nap so you can pay at least part of it down, Dement says. Invest in a white-noise machine to help snooze through the din of lawn mowers and your kids' afternoon games in the yard.
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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, says Lisa Shives, MD, sleep expert and founder of North Shore Sleep Medicine. "This and other research shows that going to bed late can be bad for your mood and your overall health."
Energy fix: If you want to shift back your bedtime, start gradually: head to bed 15 to 30 minutes earlier every few days, and make sure the lights in your home are dim for about 2 hours before that time, says Shives. Then set your alarm to wake up 7 to 8 hours later.
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. They also wear off faster than older meds, so you're not semi-comatose in the morning. Like all medicines, sleeping pills can cause side effects (dizziness, headache, agitation), and they're not meant for long-term use.
Energy fix: Ask your doctor about the pros and cons of sleeping meds for you. If you'd prefer a drug-free alternative, consider cognitive-behavioral therapy (CBT); long-term, it can be more effective than pills at combating insomnia. CBT trains insomniacs to avoid bad habits and counterproductive worries about lost sleep. Usually the therapy runs from four to eight sessions, but some patients find relief with as few as two. The downside of CBT: It can cost hundreds per session and, unlike pills, may not be covered by insurance.
http://health.yahoo.net/rodale/PVN/9-sleep-myths-that-make-you-tired
