Sleep deprivation steals your energy, sours your mood, and turns your brain to mush. And then there’s the toll it takes on your appearance. There’s virtually nothing more irritating than having your colleagues inform you of what you already know—that you look exhausted.
Lack of sleep—whether from insomnia or just staying up way too late—also makes it more difficult for every cell in your body to properly absorb blood sugar. Getting insufficient shuteye blunts your body’s sensitivity to insulin. In one study, people who got 5½ hours or less of sleep were 40 percent less sensitive to insulin than those who got nearly 8 hours a night. In another, researchers found that people who averaged only 4 hours of sleep demonstrated the kind of insulin resistance usually found in old age. Over time, insulin resistance leads to metabolic syndrome—the prediabetic condition that hurts your cardiovascular system, your memory, and even your fertility—and to diabetes itself.
Another reason we continue to toss and turn: There’s plenty of false information out there about how to pursue a good night’s sleep. Read on as we bust some of the biggest sleep myths and give smart solutions to common sleep problems.
Think most experts agree on this one? Wrong! “Asking how much sleep a healthy adult needs is like asking how many calories a healthy adult needs,” says Michael Perlis, MD, director of the University of Rochester’s Sleep and Neurophysiology Research Lab. “It depends.” Since our sleep requirements are partly inherited, some of us need more—or less—than others.
It’s one of the most contentious issues in sleep research today. When sleep researcher Daniel Kripke, MD, from the University of California, San Diego, argued at a recent conference that getting less than 8 hours a night might be beneficial, “it practically started a food fight,” recalls Phil Eichling, MD, an eyewitness at that conference and a sleep researcher at the University of Arizona College of Medicine.
Dr. Kripke has good reasons for giving the thumbs-down to the 8-hour rule. He conducted one of three studies that found that people who slept either 8 hours or more—or 6 hours or less—ran significant risks of dying of heart disease, stroke, or cancer. The highest risk was found among those who slept the longest. (Critics say long sleepers probably have underlying health problems that are the real problem, such as diabetes, depression, heart disease, or even cancer.)
Your best bet is to figure out what your body needs. Keep a diary for the next week or two, logging how much snooze time you get at night and how alert you feel the next day—without the use of stimulants such as a caffe latte or a splash of cold water on the face in the afternoon. If you need stimulants to keep you awake, you’re not getting enough sleep.
Fluffy curls around your head all night. Fido’s bladder demands outdoor bathroom trips at 3:00 and 5:00 a.m. Up to 25 percent of insomniacs may be able to blame their pets for their sleep problems, conclude researchers at the Mayo Clinic Sleep Disorders Center in Rochester, Minnesota, who surveyed 300 patients. How to stop pet-induced insomnia:
• Invest in a white-noise device or turn on a fan or air conditioner to help disguise your pet’s night noises.
• Provided your pet is healthy and has no bladder or urinary tract conditions, she should be able to wait until sunup. Take away her water bowl a few hours before bedtime, and make sure she “goes” before bed. Then, when she asks to go out, delay taking her for 10 to 15 minutes. Every 3 or 4 nights, delay an extra few minutes.
• Invest in an animal crate—talk with your veterinarian about the best size for your pet and how to introduce Fido to his new night spot.
It’s normal to feel slightly less energetic in the afternoon, due to your circadian rhythms of sleepiness and wakefulness. But if your head starts drooping while your boss is going over last month’s figures or your adorably earnest preschooler is explaining why Superman bests Batman, you need more sleep. The difference between less energetic and downright drowsy? If your eyelids feel heavy, you’re tired, says William C. Dement, PhD, the Stanford University scientist known as the father of sleep research.
You may even be running a significant “sleep debt.” That’s sleep research lingo for the total hours of sleep you’ve lost, one sleep-deprived night after another. Here’s how it happens: If you need 8 hours of sleep and get only 7 each night, after a week you’ve lost the equivalent of almost a full night’s sleep. That’s your sleep debt. And it’s cumulative. One expert estimates that the average sleep debt among Americans is 500 hours a year!
After losing the equivalent of 1 night’s sleep over the course of a week, however, your body will respond as if you’d pulled an all-nighter: You may experience waves of extreme fatigue; itchy, burning eyes; emotional fragility; loss of focus; even hunger as your body tries to find a way to become energized and stay upright. Sleep debt can also cause serious health problems down the line. Some recent studies suggest that decades of chronic sleep deprivation may increase your risk of high blood pressure, heart disease, and diabetes—by speeding age-related changes in the way your body uses glucose.
If you’re like millions of time-starved Americans, you’re stealing sleep time to finish work from the office, answer e-mails, pay bills, do laundry, or just have some quiet time. This bad habit is the number one cause of daytime sleepiness in the United States, says Carl E. Hunt, MD, director of the National Institutes of Health National Center on Sleep Disorders Research in Bethesda, Maryland.
To repay your sleep debt—and avoid future problems—your first step is to determine what’s behind it. The remedy will depend on the right diagnosis. Consider these questions.
• Do you take more than 30 minutes to fall asleep at night?
• Do you awaken in the middle of the night and have trouble getting back to sleep?
If the answer to either or both is yes, and it’s happening 3 or more nights a week, insomnia is piling up your sleep debt. Skip the rest of this section and go straight to myth #3 for advice, because the Rx for insomnia is very different from remedies for other sleep problems.
Not an insomniac? Lots of things could be keeping you up or interrupting your sleep occasionally: worry, a child with nightmares, a pet hogging the pillow, a snoring spouse, even tree branches brushing against your house. One good night’s slumber will correct that. But if you’re cheating yourself of sleep time “to get things done,” it’s time to pay up … and stay out of debt.
Take a week or so to experiment. Keep your rising time the same, but move your bedtime ahead an hour for 3 or 4 days—say, from midnight to 11 o’clock. If you’re still waking up tired and lurching to Starbucks in midafternoon, move your bedtime another 45 minutes to an hour earlier. Staring at the ceiling for 30 minutes before you drift off? Shift your new bedtime later in 15-minute increments until you hit your magic hour. How will you know? You’ll wake up refreshed, you’ll feel in top form at work, and decaf will do.
If you snore every night and you’re overweight, see your doctor. A study of almost 70,000 nurses found that those who sawed wood regularly had more than twice the normal risk of developing type 2 diabetes, regardless of their weight. Regular deep snoring triggers the release of catecholamines, hormones that can promote insulin resistance, notes researcher Wael K. al-Delaimy, MD, PhD, of the Harvard School of Public Health. Sleep apnea, a condition in which you actually stop breathing numerous times a night, may have the same effect, he says.
Step away from the bed! If you suffer from insomnia, all three of those “remedies” could make your tossing and turning much worse, says Kimberly Cote, PhD, a sleep researcher at Brock University in Ontario.
Blame it on something called the sleep homeostat. A hardwired system controlled by brain chemicals, it’s not unlike your appetite. 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, you’re not going to feel tired if you go to bed earlier or nap.
Instead, try going to bed an hour later than usual to make yourself more tired. If you absolutely must nap—perhaps because you’re exhausted and have a long drive ahead of you—make up for it by postponing bedtime for the amount of time you napped. Feeling anxious about sleep—or other worries? Try counting long, slow breaths while you lie in bed. Or visualize a pleasant and relaxing experience, such as lying on a deck chair on a cruise ship in the Caribbean. Still can’t settle down? Leave the bedroom. The idea here is to break the association between bed and anxiety. Try reading or doing some other enjoyable but low-key activity. Other sleep tricks that work:
Take a warm bath just before you go to bed. Bathing will elevate your body temperature, but lying down will make it drop because your muscles relax and produce less heat. Sleep tends to follow a steep decline in body temperature.
Exercise. In a number of studies, exercising 30 to 45 minutes during the day or evening helped insomniacs enjoy better and somewhat longer sleep. Why exercise seems to help is still unclear, though one possibility is that it has effects similar to sleeping pills. If exercising in the evening seems to get you keyed up, move your workout to earlier in the day.
See your doctor. If your insomnia is chronic, make an appointment with your family doc. He can diagnose and treat any contributing health problems or refer you to a sleep center.
A 10-minute nap is your best midday recharger. In an Australian study, 12 university students had either no nap, a 5-minute nap, a 10-minute nap, or a 30-minute nap following a short night’s sleep. Ten minutes is perfect because you recharge without falling into a deep, tough-to-wake-up slumber.