Dozens of small medical studies have shown that napping for about 30 minutes to an hour in the early afternoon increases a person's productivity, alertness and sometimes even their mood.
Still, unsanctioned napping — or to put it more precisely, "drowsiness" — on the job actually costs U.S. businesses $18 billion a year in lost productivity, according to a recent report in the Minneapolis Star-Tribune.
The findings raise the question of when it is acceptable for someone to take a quick nap, and when does it cross the line and become unacceptable.
In European countries such as Spain and in many Latin American countries, an afternoon siesta is, in fact, considered normal. Even local shops close in the afternoon for a couple of hours, when it's hard to get any business done.
In this tough economy, companies have actually begun clamping down on "napping." The Wall Street Journal recently cited a study to be released next month by Circadian Technologies of Lexington, Mass. In the study, 52 percent of firms told researchers they had reprimanded or even suspended office-nappers. That's an increase of 38 percent from 2002.
But can naps do a worker good?
A 2002 Harvard University study showed that worker burnout set in as a day of training wore on. Workers performed increasingly poorly over the course of four daily practice sessions on a visual task that involved having subjects report the orientation of three diagonal bars against a background of horizontal bars on a computer screen.
But allowing subjects to take a 30-minute nap after the second session prevented further deterioration and a one-hour nap actually boosted performance in the third and fourth sessions back to normal levels, the study found.