Written by: Lindsay Dorn, REEGT, RPSGT, Agnesian Center for Sleep Disorders
More than 85 percent of mammals are polyphasic sleepers, meaning that they sleep for short periods throughout the day. Humans are part of the minority of monophasic sleepers, meaning that our days are divided into two distinct periods, one for sleep and one for wakefulness. It is not clear that this is the natural sleep pattern of humans. Young children and elderly persons nap, for example, and napping is a very important aspect of many cultures.
As a nation, the United States appears to be becoming more and more sleep deprived. And it may be our busy lifestyle that keeps us from napping. While naps do not necessarily make up for inadequate or poor quality nighttime sleep, a short nap of 20 to 30 minutes can help to improve mood, alertness and performance. Nappers are in good company: Winston Churchill, John F. Kennedy, Ronald Reagan, Napoleon, Albert Einstein, Thomas Edison and George W. Bush are known to have valued an afternoon nap.
- A short nap is usually recommended (20 to 30 minutes) for short-term alertness. This type of nap provides significant benefit for improved alertness and performance without leaving you feeling groggy or interfering with nighttime sleep.
- Your sleep environment can greatly impact your ability to fall asleep. Make sure that you have a restful place to lie down and that the temperature in the room is comfortable. Try to limit the amount of noise heard and the extent of the light filtering in. While some studies have shown that just spending time in bed can be beneficial, it is better to try to catch some zzz’s.
- If you take a nap too late in the day, it might affect your nighttime sleep patterns and make it difficult to fall asleep at your regular bedtime. If you try to take it too early in the day, your body may not be ready for more sleep.
- Naps can restore alertness, enhance performance, and reduce mistakes and accidents. A study at NASA on sleepy military pilots and astronauts found that a 40-minute nap improved performance by 34 percent and alertness 100 percent.
- Naps can increase alertness in the period directly following the nap and may extend alertness a few hours later in the day.
- Scheduled napping has also been prescribed for those who are affected by narcolepsy.
- Napping has psychological benefits. A nap can be a pleasant luxury, a mini-vacation. It can provide an easy way to get some relaxation and rejuvenation.
In spite of these benefits, napping isn’t always the best option for everyone. For example, some people have trouble sleeping any place other than their own bed, making a nap at the office or anywhere else unlikely. Other people simply have trouble sleeping in the daytime; it could be that certain individuals are more sensitive to the midday dip than others – those who are may feel sleepier and have an easier time napping. Here are some other negative effects:
- Naps can leave people with sleep inertia, especially when they last more than 10 to 20 minutes. Sleep inertia is defined as the feeling of grogginess and disorientation that can come with awakening from a deep sleep. While this state usually only lasts for a few minutes to a half-hour, it can be detrimental to those who must perform immediately after waking from a napping period. Post-nap impairment and disorientation is more severe, and can last longer, in people who are sleep deprived or nap for longer periods.
- Napping can also have a negative effect on other sleeping periods. A long nap or a nap taken too late in the day may adversely affect the length and quality of nighttime sleep. If you have trouble sleeping at night, a nap will only amplify problems.
- One study has indicated that napping is associated with increased risk of heart failure in people already at risk.