How to "pay off" sleep debt.

• Position: Your Life - Brief Article

Here is some advice for staying alert long after April 7, the day clocks spring forward one hour and most Americans lose an hour of sleep. "If you're young, sleep an hour later on Sunday; if you're older, go to bed an hour early," suggests William C. Dement, director of Stanford (Calif.) University's Sleep Disorders Center and professor of psychiatry and behavioral sciences. He is quick to point out that, for the 60,000,000 Americans who suffer from sleep debt, daylight-saving time isn't the culprit. "If you're well rested, losing that one hour of sleep when daylight-saving time begins won't make a major difference. Don't worry about it," he maintains.

However, most people incur a sleep debt because they don't get enough sleep over time, Dement says. "A debt builds up if you sleep less than your personal need--from six to 10 hours a day, depending on individual variation--over the course of many nights. The good news is that you can repay the debt without interest. Someone who needs 10 hours of sleep could pay back a 10-hour debt over 10 days by sleeping one extra hour each night. You can catch up Aster--for example, repaying six hours by sleeping 15 hours--though only actual sleep counts. Lying in bed and staring at the ceiling won't help repay the debt.

"To make the most of the time in bed, we recommend that older...