Jan. 14, 2002 -- How much sleep do you really need? No standard answer exists. Generally, researchers agree that "optimal" sleep is the amount that leaves you feeling awake and alert all day long. Most people need a full eight hours; some do well on six.
In Power Sleep (HarperCollins, for about $13), Cornell University psychologist James Maas suggests a "sleep quotient" experiment: For one week, go to sleep a full eight hours before you need to get up. If you rise rested and ready to go -- and feel that way throughout the day -- you've gotten enough sleep. If not, try changing your bedtime by adding to it (or subtracting from it, if necessary) by 15 to 30 minutes for a week. Eventually, you should discover the amount of sleep that works for you.
Alternatively, you might try keeping a sleep diary. Record the time you sleep and how you feel the next day to find the best sleep pattern. When your snooze schedule reaches perfection, you'll wake up in the morning at the right time, even without an alarm clock.
Your sleep style is partly genetic. Several "clock" genes influence our natural sleep/wake cycles, or circadian rhythms. At night, when it's time to rest, these genes start winding your body down, increasing drowsiness, for example, and lowering your temperature and heart rate. Last fall, Emmanuel Mignot and colleagues at Stanford University found telltale differences in one clock gene among people who were night owls and those who were morning larks. Tuning into your natural rhythms may be the secret to blissful sleep -- and busy days.
It worked for Carol Ezzell, an editor in New York. Never one to embrace the dawn, Ezzell has designed a work schedule around her creative highs. She arrives at the office around 10:30 a.m and stays until 6:30 at night. "I'd rather eat a quick lunch and work late than fight to be productive early in the day," Ezzell says. "I just don't do good work in the early morning."
It doesn't really matter when you go to sleep or wake up, researchers say, as long as you're consistent. Nod off around 10:30 every night, and you'll snooze more quickly and feel alert the next day. Bounce bedtimes around, however, and you're more likely to feel grumpy and drowsy. Sleeping in on Saturday morning also can short-circuit your sleep cycle by making it difficult to fall asleep that night. Then Sunday becomes a bear. As Maas puts it, "You cannot make up for large sleep losses during the week by sleeping in on weekends any more than you can make up for lack of regular exercise and overeating during the week by working out and dieting only on the weekends."
You can, however, reclaim a few z's. Short naps -- tucked behind an office door, or while the kids are at school -- are one way. About half the world takes an afternoon siesta, and with good reason: Body temperature and alertness dip during mid-afternoon, a sneak preview of bedtime biology. A short nap -- 15 to 30 minutes -- will help you perk up, while a longer nap sails you into deep sleep and actually may make you groggy. If naps don't work, try going to bed half an hour earlier at night and waking at your normal time. This gradual approach will keep your sleep cycle in sync while you rest up.
Healthy habits outside the bedroom can improve sleep, too. Take exercise. In one study, Michael Vitiello, a sleep researcher at the University of Washington, found that people who ran or walked 40 minutes, three days a week, experienced longer periods of deep sleep than a more inert comparison group. This and other studies suggest exercise somehow alters metabolism, setting your body up for more restful sleep.
To pump up your slumber, exercise during the day, before dinner, Vitiello says. And start slowly. "Don't go from being a couch potato to walking 15 miles," he cautions. "That's too much stress on your body, and you probably won't sleep well."
In fact, Vitiello notes, dreamy sleep is just one more reason to boost your all-around fitness -- inside and out. You'll feel your best if you eat right, exercise and tackle the stresses of the day. It's old advice. But it's one route to happiness -- morning, noon and night.
10 Tips to Get More Sound Sleep
- Go bland before bedtime. To fall asleep quickly, avoid caffeine, nicotine and alcohol for at least four hours before you go to bed.
- Be predictable. Go to bed around the same time every night, and try to follow a similar routine.
- Don't toss and turn. If you can't sleep after 20 minutes, get out of bed and do something else.
- Save the bed for sleep and sex. Avoid paying bills, reading the paper or watching TV in bed.
- Take a bath. When your body gets ready for sleep, your temperature drops. A bath may nudge your bedtime biochemistry along.
- Exercise early. If you exercise, do it before dinner, not after.
- Get dark. People usually sleep best in a cool, dark environment. Invest in heavy drapes if city lights glare outside.
- Grab a snack. It's hard to sleep hungry, so try a light snack before bedtime. Some researchers think tryptophan, a chemical found in milk, naturally induces sleep.
- Cut naps short. If you have trouble falling asleep, consider avoiding naps. At the very least, limit them to less than an hour before mid-afternoon.
- Deal with stress. If daytime troubles keep you awake, try jotting notes about ways to deal with them. Leave stress at the bedroom door, if you can.