Taking a nap isn't child's play, according to a host of sleep experts interviewed by the Wall Street Journal's Sumathi Reddy.
Specifically, length of time, sleeping position, and time of day all play a role in crafting the "perfect nap."
Anatomy of the nap
The Journal notes that there are several sleep stages, which the brain cycles through every 90 to 120 minutes. Those stages include light, intermediate, and slow-wave sleep, as well as rapid eye movement (REM) sleep, which is associated with dreaming.
As a result, different nap lengths can provide different benefits, according to Sara Mednick, a psychologist at the University of California, Riverside.
- Short nap: A 10- to 20-minute nap provides a quick boost of alertness.
- Hour-long nap: This length of nap aids in memory processing, but can leave the napper groggy.
- 90-minute nap: This length aids in creativity and building procedural memories, like learning to ride a bike.
Sleep experts also recommend napping between the hours of 1 p.m. and 4 p.m.—any later and the nap could interfere with nighttime sleep. They also recommend drinking a cup of coffee or other caffeinated drink just before napping in order to wake up feeling alert, and one sleep scientist—the University of Pennsylvania's David Dinges—recommends sleeping partially upright, too.
"You have to be deliberative about when you're going to nap, how long you're going to nap and if you're trying to use the nap relative to work or what you have coming up," Dinges said.
Which nap is most effective?
Experts disagree as to which naps may be most beneficial, but Leon Lack—a psychologist at Flinders University
in Australia—says a 10-minute nap provides the most bang for your buck.
For his 2006 study published in Sleep, Lack compared 24 participants' mental-processing after waking up from naps ranging from 30 seconds to 30 minutes.
- The 10-minute nappers' mental sharpness was apparent "right away," Lack said, and the effect lasted for another 2.5 hours.
- The 20- to 30-minute nappers, meanwhile, often felt groggy and struggled to focus.
A 2012 study found that 60-minute nappers performed far better on memory tests than 10-minute nappers—even outperforming 10-minute nappers up to a week later, according to lead author Sara Alger of Notre Dame University.
Snoozing on the job
Employers are also recognizing the importance of napping by providing their employees with options to nap during the work day, Reddy writes. Companies such as Google
and the Huffington Post
have installed specially designed sleeping pods from MetroNaps
. The pods retail for $8,995 to $12,985 (Reddy, Journal
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