The potential health aspects of taking naps during the day have been discussed for years. Yet, many still believe that napping during the work day is synonymous with laziness. However, many cultures build catnaps into their routines. Furthermore, dozens of studies have shown that catching a few winks during the daylight hours is healthy.
David Dinges is the chief of the Division of Sleep and Chronobiology in Psychiatry at the University of Pennsylvania, Perelman School of Medicine.
He explains how to optimize midday snoozing.
Dr. Dinges says that naps come in two forms: voluntary and involuntary.
A voluntary nap is when a person makes a conscious decision to catch some shut-eye before continuing the duties of the day.
"Those are naps that fill in additional sleep needs, and they have many health benefits," he says.
Involuntary naps, often the kind that happen when you're caught napping, are thought to be a mark of someone who lacks the fortitude to stay awake. Dr. Dinges says that voluntary or intentional is the best way to fill up a person's "sleep tank."
"If you live on a schedule where you only get six hours of sleep a night and you get 45 minutes of intentional naps a day, you don't develop much of a sleep debt," he says.
Doctors generally recommend that adults get at least seven hours of sleep in a 24-hour period.
Studies have shown that work hours and commute times are the two of the largest reasons for sleep debt in Americans, Dr. Dinges says. That's why when sleep-deprived people get on a bus or train to commute home, they frequently doze off.
The first sign of falling asleep is that the muscles relax. "First go the arms, then the hands, then the eyelids," says Dr. Dinges.
His book is called Sleep and Alertness: Chronobiological, Behavioral and Medical Aspects of Napping. It does a deep dive into the science of taking short naps.
"Next goes the neck, so your head falls over," he continues. That triggers the part of your brain that feels when you're falling, which is why you wake up.
Such involuntary sleep attacks don't provide much benefit, because "the brain doesn't progress into sleep far enough for recovery, so it's more like a disturbed night of sleep," Dr. Dinges says.
One way to prevent them is to drink caffeine, a natural stimulant that aids in staying alert. A better way is to set yourself up for a proper, preventative nap.
Experts on sleep believe that humans are programmed to sleep at night, and to take a nap in the midafternoon, although scientists don't really know why.
According to Dr. Dinges, "There is no melatonin triggering sleep. It just seems to be this harmonic phenomenon." He says that the consensus among his colleagues is that human civilization evolved mostly in equatorial climates, where it got very hot later in the day. Napping during the extreme heat optimized work performance.
So, how do you make the most of this apparently biological need? Well, find a cool, dark, quiet place to lie down and put your head down. Also, be sure to ditch all your electronic devices. The light from a computer screen can actually mess with your ability to sleep.
You also want to make sure you're in a place where you "feel" safe. So you might want to avoid public places, or places in the office where you are visible, like a glass-walled office. Remember to set an alarm so you don't oversleep. Set it for anywhere from more than 15 minutes to 60 minutes. Any longer may affect your sleep at night.
It is believed that even a 15 minute nap is enough to relieve some sleep pressure, since the brain goes into a light, non-REM sleep pattern, which in turn contributes to recovery.
"Being awake is like carrying a bag on your back," says Dr. Dinges. "The longer you're awake, the more bricks you add. When you take a nap, you remove some of those bricks."