Is there any real benefit to power napping?

Quick, short naps may not be for everyone, but if you find them rejuvenating, more power to you, says Robert A. Hicks, Ph.D., a professor of psychology at San Jose State University. "People need to get somewhere between seven and eight hours of sleep per night for normal functioning, and some of that can be accomplished with naps," says Hicks. But napping can become a problem if it interferes with your ability to fall asleep at night. "I'd rather have you be tired during the day and get a good night's sleep," he says.

Sleep comes in several stages. Stage one is a light, transitional phase we pass through when first falling asleep and when beginning to wake up. Stage two is not well understood, but researchers do know there's a fair amount of it. Stages three and four are slow-wave sleep and are very important to restoring your energy. In the last third of a seven- to eight-hour night, REM sleep occurs. "During this time we dream—and researchers believe it plays a role in memory consolidation and maybe even stress management," says Hicks. If your sleep time is shortened, however, REM (rapid eye movement) sleep gets cut out. "With a power nap, you're not likely to get REM sleep," says Hicks, but you may get some slow-wave sleep that will have a restorative effect on your body.