The 20-minute nap increases alertness and motor skills.
[7] Various durations may be recommended for power naps, which are very short compared to regular sleep. The short duration prevents nappers from sleeping so long that they enter the slow wave portion of the normal sleep cycle without being able to complete the cycle. Entering deep, slow-wave sleep and failing to complete the normal sleep cycle, can result in a phenomenon known as
sleep inertia, where one feels groggy, disoriented, and even more sleepy than before beginning the nap.
People who regularly take these short naps may develop a good idea of the duration which works best for them, as well as which tools, environment, position, and associated factors help produce the best results. Power naps are effective even when schedules allow a full night's sleep. Mitsuo Hayashi and Tadao Hori
[8] have demonstrated that a nap improves mental performance, even after a full night's sleep.
A
caffeine nap is a short nap that is preceded by the intake of caffeine. In a driving simulator and a series of studies, Horne and Reyner investigated the effects of cold air, radio, a break with no nap, a nap, caffeine pill vs. placebo and a short nap preceded by caffeine on mildly sleep-deprived subjects. The last mentioned was by far the most effective in reducing driving "incidents" and subjective sleepiness. Caffeine in coffee takes up to a half-hour to have an alerting effect, hence "a short (<15min) nap will not be compromised if it is taken immediately after the coffee."
Benefits
Napping has been found to be beneficial. Napping for 20 minutes can help refresh the mind, improve overall alertness, boost mood and increase productivity.
[2] Napping may benefit the heart. In a six-year study of Greek adults, researchers found that men who took naps at least three times a week had a 37 percent lower risk of heart-related death.
[3]
Scientists have been investigating the benefits of napping for years: the 20-minute nap, as well as sleep durations of 1–2 hours. Performance across a wide range of cognitive processes have been tested. Studies demonstrate that naps are as good as a night of sleep for some types of memory tasks. A
NASA study led by
David F. Dinges, professor at the
University of Pennsylvania School of Medicine, found that naps can improve certain memory functions and that long naps are better than short ones.
[4] In that NASA study, volunteers spent several days living on one of 18 different sleep schedules, all in a laboratory setting. To measure the effectiveness of the naps, 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,
Robert Stickgold, and colleagues at
Harvard University for a study which showed that a midday snooze reverses
information overload. Reporting in
Nature Neuroscience,
Sara Mednick, Stickgold and colleagues also demonstrated that, in some cases, a one-hour nap could even boost performance to an individual's top levels. The NIMH team wrote: "The bottom line is: we should stop feeling guilty about taking that 'power nap' at work."
Negative effects
Naps are not recommended for those suffering from
insomnia or
depression [1] in order to avoid worsening nocturnal sleep.
***ookie, so my main reason for posting this is only because i tend to get rly tired from time to time, especially during the day. I'm actually not quite sure what my 'sleep' issue is...i can't for some odd reason sleep 8 hrs, or anywhere along that that lines...i'm usually 'good' on anywhere from 3-4(max) hrs. (and i know that's not good/healthy for you....but i'm working on it!)
i guess i might try to take a 20 minute 'power nap' during my lunch break...and still have 40 minutes to eat ~_^
^^oh, btw: my source for this article is wikipedia (gotta love it!)
yup yup