Researchers at Flinders University in Australia are currently
researching just this question! From [
"Although "Power Naps" are now being recommended in work places to
overcome daytime sleepiness, there is very little scientific research
to justify them. We compared the effects of no nap with a brief 10
minute nap and longer 30 minute nap in the afternoon following a night
of sleep restriction. Following the 10 minute nap there was an
immediate significant increase of subjective and objective alertness
and mental performance which was sustained for the hour of testing
following the naps. Immediately following the 30 minute nap there was
a continued depression of alertness similar to the no nap condition.
However, after 35 minutes there was some recovery of function and an
hour after the 30 minute nap alertness had increased to the same level
of improvement as that following the 10 minute nap. We are now
exploring how brief a nap can be and still be significantly beneficial
to improved alertness and cognitive performance. This research not
only has theoretical implications for the biological determination of
sleepiness, it will have practical significance for all those
experiencing daytime sleepiness in a variety of circumstances some of
which may be extremely dangerous."
On the original web page, there are multiple citations to scientific
articles on this phenomenon, which may be of interest to you. My own
reading of the above is that preliminary research indicates that very
short afternoon naps appear to increase alertness, and that increased
alertness is likely correlated with increased productivity.
Professor Leon Lack's web page with his contact information at
Flinders University is here: [
WebMD features an article at [
] which references other scientific publications to make the following
"But does a nap in the afternoon make up for midnight tossing and
Yes, according to some studies, including those conducted at the Henry
Ford Hospital's Sleep Disorders and Research Center in Detroit.
Napping is "clearly beneficial to someone who is a normal sleeper but
who is getting insufficient sleep at night," says center director
Timothy Roehrs, Ph.D. "We don't understand the underlying
neurobiology, but sleep time is cumulative."
Roehrs says his group compared the alertness of people who slept eight
hours a night to that of people who slept less but took a nap during
the day. Both groups were equivalent, he says."
Note that the definition of a "nap" in the WebMD article is slightly
different from that in Professor Lack's research. The WebMD article
discusses somewhat longer naps during the day.
Dr. William Anthony, who is cited in the WebMD article, has his own
webpage at [ http://www.napping.com/workplace.html ] where he promotes
his book advocating naps in the workplace. This page quotes a
consultant as saying that "We have experienced an increase in
productivity, and seen less human error as a result of our nap room."
An article by Jordan Hass on Trendscope [
http://www.trendscope.net/article.cfm?ID=108 ] compiles various
research into one tidy article describing the potential impact of
afternoon naps on productivity.
"Napping during the day is far from a new concept and "siestas" remain
common in many countries around the world. Research proves that the
human need for an afternoon nap is genetic and has nothing to do with
sleeping and eating habits...Workers who take a 20-minute nap instead
report they go back to work with more energy and enthusiasm.
The National Sleep Foundation study found that, on average, $18
billion is lost annually because of employee drowsiness. Corporations
that allow short naps report reduced incidents of accidents and
errors, and claim that it's worth the slightly shorter workday,
because napping improves overall productivity...The best nap for
recharging, he says, is one that lasts between 10 and 30 minutes;
longer than that and it's more difficult to regain alertness."
Given all this, it seems obvious that employers should welcome short
afternoon naps, right? Wrong. While I wish this was the case, there is
a profound bias that napping is a sign of laziness, and thus should
not be encouraged in the office. I certainly hope that you can break
the trend with the citations that I've supplied you.
Good luck in your research! Please ask for clarification if you need
Google Search: "afternoon nap" "circadian rhythm"
Google Search: "afternoon nap" productivity