Next weekend, most Americans "fall back" to standard time and gain an extra hour. How to spend it? "Use it to pay off your sleep debt," urges Ralph Downey III, chief of sleep medicine at Loma Linda (Calif.) University Medical Center. "That extra hour of sleep will rejuvenate you both physically and mentally."

What the heck is a "sleep debt"? "That's the difference between your body's need for sleep and the actual amount of sleep you get," Downey says. "So, if you require eight hours but only get six, your sleep debt is two hours."

Beyond fatigue and crabbiness, research links chronic sleep deprivation with health problems, including:
-- Obesity;
-- Greater risk of developing cardiovascular disease and diabetes; and
-- Worse eye-steering coordination, which ups the odds you'll crash your car.

Tips for better sleep:
-- Avoid napping during the day.
-- A few hours before bedtime, steer clear of caffeine, alcohol, nicotine, heavy meals and exercise.
-- Relax with soothing rituals before going to bed.
-- Keep your bedroom dark, quiet and a little cool.