Studies suggest that many people experience significant drops in energy and concentration levels approximately eight hours after waking up from regular sleep. This drop typically occurs during late afternoon business hours, so there is often a loss of productivity as well. Workers may experience a loss of mental focus, visual acuity or physical stamina. To counteract these effects, a number of people take a short sleep break known as a power nap.
A power nap provides many of the same recuperative benefits of regular sleep, but in far less time. A power napper is not trying to fall into a deep form of sleep for a few hours, but rather reach the second stage of a five stage sleep cycle within an hour's time or less. In fact, many sleep experts suggest an effective power nap should only last 20-30 minutes in order to avoid the grogginess associated with interrupted sleep cycles.
During the first and second stages of a normal sleep cycle, the body's muscles have an opportunity to relax while the napper's mental state is refreshed. On average, most people reach the end of the second stage of sleep within an hour or less. Setting an alarm for that amount of time should prevent a power napper from entering deeper stages of sleep which involve dreaming and physical recuperation. Waking up from stage three, four, or five of the sleep cycle prematurely can leave the napper feeling even more groggy and less focused than before the nap.
Taking a power nap involves finding a distraction-free area and setting an alarm for at least 20 minutes, but no more than one hour. Many workers take power naps during their lunch breaks, or during extended downtime in their offices. A power nap is closer to meditation than a leisurely nap at home, however. The goal is to reach a state of mental and physical relaxation with the assurance that an alarm will not allow the napper to fall completely asleep. Ideally, a power napper should come out of the nap feeling mentally refreshed, not groggy or sleep-deprived.
A power nap can also help drivers on long trips. In order to avoid driver fatigue, a driver should pull off to a designated rest area periodically and take a short power nap before resuming the trip. Sleep deprivation combined with the hypnotic effects of highway driving can reduce a driver's reaction time and mental acuity. Some driving experts suggest taking a legal caffeine pill or caffeine-laden beverage just before taking a power nap. The caffeine will not have time to take effect during the nap, but it will start to work just as the driver goes back on the road.
Many companies around the world now recognize the benefits of a power nap, and they often encourage employees to take one at some point during working hours. Taking a short power nap during the day should not have an effect on a person's normal sleep cycle, but a longer period of deep sleep during the day might create some difficulty falling asleep at night. If time does not permit a full power nap, some people may also benefit from a few minutes of quiet meditation.