Napping: a refresher course.
About half the people in the world, mostly in warm climates, take an afternoon siesta each day, but napping is not a viable option for most Americans with conventional jobs. Some of us who have flexible schedules do use naps to renew energy, or occasionally to catch up on lost sleep. Just think of Winston Churchill, who used to nap in the afternoon as a way to "press a day-and-a-hall's work into one." In addition, surveys show that about half of all college students and most retired people nap at least once a week.
Sleep researchers have learned that napping is not a sign of laziness or merely a cultural artifact. They've discovered that the urge to nap in the afternoon is nearly universal, even in people who have had a full night's sleep. This drowsiness and drop in alertness used to be attributed to eating and digesting lunch or, in warm areas, to afternoon heat. But this post-lunch dip apparently occurs whether we eat or not and in any climate. In fact, our bodies experience a slight midday drop in temperature--part of our internal biorhythms--that encourages sleepiness. Studies have shown that subjects living in isolation without any time cues naturally divide their daily sleep between one long and one short period.
Not everyone has the free-floating schedule of college students or the "naptitude" of Churchill. And not everyone likes or benefits from napping. Many people who have trouble sleeping at night find that daytime napping only worsens matters. Others find that napping leaves them more fatigued than before. If you're tempted to try napping as a pick-me-up, bear in mind:
* The ideal nap time for most people is about eight hours after waking and eight hours before nighttime sleep. That's when body temperature reaches its low point--usually between 2:00 and 3:00 P.M.
* Naps are not miniature versions of a full night's sleep. A mid-afternoon nap is primarily deep sleep, which is most refreshing. Morning naps are usually lighter sleep, while earlyevening naps are more likely to leave you groggy and make you postpone nighttime sleep.
* Studies on sleep-deprived pilots and shift workers have found that naps help reduce fatigue, increase alertness, and improve certain aspects of job performance.
* It may not be necessary to sleep during your "nap": a study at Texas A&M University found that merely lying down and resting can be as restorative as napping.
* Keep your nap under an hour: longer won't increase the benefits, and is more likely to result in the intense grogginess known as "sleep inertia." A long nap may also interfere with sleeping at night. For some people, even 10-minute naps are refreshing.
* Don't forget that other energizer-exercise. It not only has a stimulating effect (without the post-nap inertia), but is also conducive to a good night's sleep.
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|Publication:||The University of California, Berkeley Wellness Letter|
|Date:||Oct 1, 1992|
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