Sleep is a necessity, not a luxury. "For quality of life and longevity, I would definitely put good quality and quantity of sleep above the need for exercise," says psychologist Russell Rosenberg, director of Atlanta's Northside Hospital Sleep Institute. "It's right up there with diet ... and the quality of air you breathe."

Recent research shows that sleep deprivation actually harms metabolism and physiology, as well as mood, relationships and concentration, he says.

Here are Rosenberg's tips for improving your sleep:

Put slumber on your schedule, and guard it the same way that you protect time for other vital activities.

Limit activities that occur in bed to sleeping (and sex). You should associate lying in bed with falling asleep.

Create a wind-down routine that helps you relax. Avoid TV news, arguments or balancing your checkbook.

Turn your clock to face the wall. If you wake up in the middle of the night, don't fret about the time, because pressure to fall back to sleep will build, leading to anxiety and insomnia.

If you can't get back to sleep in 15 to 20 minutes, get up, do something relaxing, return to bed and start over.

Limit caffeine (found in coffee, tea, cola, chocolate, over-the-counter medications, etc.) in the evening.

Be sure to sleep alone or with your partner only. Although emotionally satisfying, sharing the bed with pets and children can disrupt your sleep.

Source: National Sleep Foundation