If you've had one or two bad nights lately, you can probably solve the problem by taking some of the measures below. These strategies may require you to change your sleeping habits, but the effort is well worth it in the long run.

　　1. Make your bedroom a haven for sleep. Your room should be quiet and sufficiently dark, because darkness prompts the pineal gland to produce melatonin, the hormone that regulates circadian rhythms (your 24-hour body clock). Heavy drapes can help keep the light out, and a fan or white-noise machine can help drown out any annoying sounds. Cool temperatures help you sleep, so set your thermostat appropriately. For better air circulation, open a window or use a fan. If the air in the room is too dry, buy a humidifier.

　　2. Become a creature of habit. A nighttime routine can be very effective in letting your body know when it's time to sleep. Go through whatever rituals help you get mentally prepared for sleep. (Read a few pages of your novel, spend 5 to 10 minutes on personal grooming, meditate, stretch.) It's also critical to go to bed and get up at the same time every day -- even on weekends.

　　3. Reserve your bed just for sleeping and sex. Avoid working, paying bills, reading, or watching television in bed. If you associate your bed only with sleep, you'll be more likely to fall asleep when you get under the covers for the night.
　　4. Tame your tummy. Going to bed either hungry or too full can disrupt your sleep. Don't have a big meal too close to bedtime or the digestion process might keep you awake. Also, if you lie down after stuffing yourself you can end up with gastric reflux -- stomach acid backing up into the esophagus. If you're hungry, have a snack rich in carbohydrates, which trigger the release of the brain chemical serotonin, associated with relaxation. Try a graham cracker or bowl of cereal. Pair it with some milk or a slice of turkey, both rich in the amino acid tryptophan, which also induces sleep.

　　5. Watch the caffeine. Too much caffeine throughout the day, even if it's not consumed right before bedtime, can contribute to fitful slumber. Once you hit 50, your metabolism slows, so caffeine may stay in your system longer -- up to 10 hours. Limit yourself to two cups of tea, coffee, or cola, taken at least 6 hours before bedtime. If that doesn't work, try cutting out caffeine altogether.

　　6. Tap the exercise answer. It's a simple fact: If you're physically tired at the end of the day, you'll sleep better. In a study from Stanford University School of Medicine, a group of 50- to 76-year-olds who had complained of sleep problems began moderate exercise for about half an hour four times a week. Compared with a similar group of people who didn't exercise, the more active group slept an average of one hour more each night, took less time to fall asleep, spent less time napping, and reported an overall improvement in sleep quality. Outdoor exercise is especially helpful. By exposing yourself to sunlight (particularly in the afternoon), you help prevent midday sleepiness and reinforce your body's circadian rhythms. Exercise at least three hours before bedtime.liuxuepaper.com