Little known but widespread (an estimated 9 percent of women and 12 percent of men in the United States suffer from it), sleep apnea is a condition that causes breathing to stop five to 30 times per hour.

Fuel early, fuel well. A good breakfast sets the stage for sustained energy through-out the day, influencing whether or not you reach for that afternoon coffee that will keep you up at night, Ross says. Start the day with a balance of protein and slow-burning or low-glycemic carbohydrates, such as whole-grain toast and a poached egg. Sticking with that protein-carb mixture, staying away from stimulants, and eating small meals consistently throughout the day help keep energy on an even keel. And beware that caffeine has a half-life of 12 hours, Breus says. An energy drink, chocolate bar, or tea or coffee consumed at noon still has some effect at midnight.

Get outside in the early afternoon. Centuries of evolutionary programming have, for reasons not completely known, prompted your innate biological clock to make you sleepy in the afternoon (siesta anyone?). “Your body has a small temperature dip between 1 p.m. and 3 p.m., which signals your brain to produce melatonin,” explains Breus. Instead of succumbing to the nap, which can exacerbate insomnia later, he suggests stepping outside into sunlight. You'll perk up, delaying that melatonin surge until you really need it.

Exercise in the late afternoon. It's true: People who get regular aerobic exercise sleep better. One Stanford University study of 29 women and 14 men age 50 to 76 found that those who did aerobics or took brisk 30- to 40-minute walks four times per week for 16 weeks fell asleep faster and slept more deeply and longer than the control group. Body temperature rises during exercise (particularly aerobic exercise) and then drops roughly five hours later, signaling drowsiness. So if your bedtime is 10 p.m., plan to work out around 5 p.m.

Dine for sleep. Breus recommends eating dinner about four hours before bedtime. Include plenty of complex carbohydrates, which enhance the transportation of L-tryptophan into the brain, where it can be made into sleep-inducing serotonin. Although a glass of wine may make you fall asleep faster, you'll sleep lighter. And if you must have a bedtime snack, limit it to less than 200 calories, no closer than one hour before bedtime. Include complex carbs and calcium, such as whole grain toast with cheese, or a bowl of cereal and milk, says Breus.

Power down. Instead of using your alarm solely to wake up, set it to go off one hour before bedtime, to remind you to settle in and prepare for tomorrow. Ross recommends journaling your thoughts “out of the brain and onto paper” so they don't race through your head as you're trying to sleep. Be sure your sleep space is as dark as possible and has no electronics nearby. Mounting research suggests that even minute amounts of light (such as from a glowing alarm clock) and exposure to electromagnetic or radio frequency fields (from laptops or cell phones) can interfere with melatonin production. One recent study of 71 people found that those exposed to wireless communication signals up to one hour before bedtime took significantly longer to fall asleep and didn't sleep as deeply. So turn off cell phones and laptops before you turn in for the night.