Power nap

A power-nap is a short sleep which terminates before the occurrence of deep sleep or slow-wave sleep (SWS), intended to quickly revitalize the subject from drowsiness. The expression power-nap was coined by Cornell University social psychologist James Maas.

Characteristics

Power-napping is thought to maximize the benefits of sleep versus time. It is used to supplement normal sleep, especially when a sleeper has accumulated a sleep deficit.

Various durations are recommended for power-naps, which are very short compared to regular sleep. The short duration of a power-nap is designed to prevent nappers from sleeping so long that they enter a normal sleep cycle without being able to complete it. Entering a normal sleep cycle, but failing to complete it, can result in a phenomenon known as sleep inertia, where one feels groggy, disoriented, and even more sleepy than before beginning the nap. In order to attain maximum post-nap performance, it is critical that a power-nap be limited to the beginning of a sleep cycle, specifically sleep stages I and II.

Scientific experiments (see Benefits section below) and anecdotal evidence suggest that an average power-nap duration of around 20-30 minutes is most effective. People who regularly take power-naps may develop a good idea of what duration works best for them, as well as what tools, environment, position, and associated factors help induce the best results. Some people take power-naps out of necessity, for example, someone who doesn't get enough sleep at night and is drowsy at work may sleep during his or her lunch break. Others may prefer to take power-naps regularly even if their schedules allow a full night's sleep. Mitsuo Hayashi, Ph.D. and Tadao Hori, Ph.D. [cite web|url=http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1440-1819.1998.tb01031.x|title=The effects of a 20-min nap before post-lunch dip|date=1998-04-01|accessdate=2008-06-12] have demonstrated that a nap improves mental performance even after a full night sleep.

Difference between a power-nap and a catnap

While a power-nap and a catnap can be considered to be synonymous in terms of duration and effect, the vernacular usage often makes a behavioral distinction: a power-nap involves a break from activity, while a catnap is of a more leisurely nature. Thus, one may take a power-nap in the middle of a busy work day, and a catnap on the couch during a lazy afternoon.

The caffeine nap

A caffeine nap [cite web|url=http://www.sleepdex.org/caffeine-nap.htm|title=The Caffeine Nap|accessdate=2007-08-24] [cite web |url=http://www.lboro.ac.uk/service/publicity/news-releases/2004/04_110_micro-sleep.html|title=Loughborough University researchers issue new warning to tired drivers |accessdate=2007-09-23 |format= |work= ] is a power nap that is preceded by the intake of a caffeinated beverage or a caffeine pill. The reasoning is that it takes about 15-20 minutes for the caffeine to take effect, so one should awaken doubly energized.

Benefits

Scientists have been investigating napping for several years, both the 20-minute power-nap and sleeps of 1-2 hours. Performance across a wide range of cognitive processes is tested. Studies demonstrate that naps are as good as a night of sleep on some types of memory tasks. However, a NASA study led by David Dinges, professor at the University of Pennsylvania School of Medicine, found that while naps improve some memory functions, they do not aid basic alertness very much. [cite web|url=http://science.nasa.gov/headlines/y2005/03jun_naps.htm|title=NASA Nap|date=2005-06-03|accessdate=2007-08-24] In the NASA study, volunteers spent days living on one of 18 different sleep schedules, all in a laboratory setting. To measure how effective the naps were, tests probing memory, alertness, response time, and other cognitive skills were used.

The National Institute of Mental Health funded a team of doctors, led by Alan Hobson, M.D., Robert Stickgold, Ph.D., and colleagues at Harvard University in a study that showed a midday snooze reverses information overload. Reporting in Nature Neuroscience, Sara Mednick, Ph.D., Stickgold and colleagues also demonstrated that "burnout" irritation, frustration and poorer performance on a mental task can set in as a day of training wears on. Their study also proved that in some cases napping could even boost performance back to morning levels. The NIMH team wrote "The bottom line is: we should stop feeling guilty about taking that "power-nap" at work." [cite web|url=http://www.nih.gov/news/pr/jul2002/nimh-02.htm|title=The National Institute of Mental Health Power-Nap Study|date=2002-07-01|accessdate=2002-07-01]

References

* Baas 1999 - "Power Sleep : The Revolutionary Program That Prepares Your Mind for Peak Performance"

ee also

*Siesta
*Nap (disambiguation page)
*Sleep
*PowerNap (recording)

External links

* [http://www.mensjournal.com/healthFitness/0601/napping_power.html Men's Journal article on power naps]