Medical research is confirming what Winston Churchill, Albert Einstein and Napoleon Bonaparte knew all along: when you start to fade, nothing beats a nap to perk you up.
Factors in addition to circadian rhythm cycles and sleep deprivation can influence the need for a nap. Poor health and eating habits, stress, exercise (or lack of it), lack of fresh air, and working under artificial lights can also induce the craving for a nap.
Whether you nap at home or work, as little as a 10- to 15-minute nap can make a positive difference in how you feel and function. There are long-term benefits, as well. One study shows a 30 percent lower incidence of heart disease in people who napped.
How long is the ideal nap? Most experts say it's anywhere from 15 to 30 minutes. It should be long enough to benefit from sleep, but not so long as to send you into deep sleep.
You're ready for a nap when you start feeling drowsy, and that commonly takes place 8 hours after you get up in the morning or 12 hours after the midpoint of the previous night's sleep.
For the average person, that time occurs somewhere between 2:00 p.m. and 4:00 p.m., which is also the lowest biorhythm point. At that time, body temperature drops and metabolism begins functioning at a minimum, and people become tired and less alert.
Statistics also show that 2:00 p.m. to 4:00 p.m. is the time period in which the most industrial, traffic, and domestic accidents occur.
If you're healthy and do not have a sleep disorder, you should be able to take a judiciously timed nap and sleep at night without any problems.
For people with sleep disorders, such as sleep apnea or narcolepsy, a nap may also prove beneficial. On the other hand, if a person can't sleep at night from insomnia, a nap during the day might add to the problem. It depends on the person.
Because many people are at work during the afternoon when the drowsy feeling sets in, they ignore the need for a nap. But it makes sense to take a quick nap at work for two reasons.
During that period, workers are not highly productive and are more error prone. And if you work through that period, some negative aspect of fatigue can emerge later.
For example, once you're home, you might fall asleep in front of the television, and studies show that evening naps may interfere with regular nighttime sleep.