So I've found myself falling victim to the spontaneous two-hour nap lately. You know, when you're totally wide awake but lay down for "just a minute" and wake up like:

As a baby, my parents praised me as a world-class sleeper, but I was never super into the nap thing. As I've progressed through college, I'd say my ability to fall asleep anytime, anywhere - planned or not - is an art form.

As I wake up from one of these glorious two hour naps today, I found myself wondering what the science behind naps and sleeping patterns in general are. This is what I found out, courtesy of the National Sleep Foundation:

1. More than 85% of mammalian species are polyphasic sleepers, meaning that they sleep for short periods throughout the day.

2. Humans are part of the minority of monophasic sleepers, meaning that our days are divided into two distinct periods, one for sleep and one for wakefulness. It is not clear that this is the natural sleep pattern of humans. Young children and elderly persons nap, for example, and napping is a very important aspect of many cultures.

3. There are types of napping - planned, emergency and habitual.

Planned napping is often used when you know you're going to be up a bit later than your normal bedtime so you need a quick rest. My mother is an expert at this. She gets up very early for work during the week, and usually continues to do so on the weekend out of habit. If she knows she's going to be out past 10:00, she usually takes a little nap beforehand to prepare.

Emergency napping is basically this:

It's when you have the intense, sudden need to take a nap, and cannot continue with whatever you were doing previously. These kinds of naps are good for combating fatigue and are very important if you are doing an activity where safety is involved, such as operating machinery or driving a car. I have talked to a few nurses who say they can take a quick ten minute nap at the flip of a switch, and it greatly improves their alertness, especially as they work through night shifts. It's better to take that snooze than make a mistake!

Habitual napping is when you take a nap at the same time each and every day, and is just part of your daily routine. We see this commonly in babies, toddlers and older adults. But hey, maybe some culture are getting it right by letting this continue through adulthood. It is common in Spanish culture to take an afternoon siesta. Basically it's a break in the middle of the day for everyone to go home, eat lunch, and chill out (napping is often involved). Businesses shut down, and everyone just relaxes. Seems awesome to me. I've also seen recently that in many primary schools in China, teachers just have students take a little snooze on their desks for about thirty minutes.

4. Naps of twenty to thirty minutes is encouraged. Anything longer than this might interfere with your ability to fall asleep at night, and is best for improving alertness. I'd have to agree, I'm usually a bit groggy after those two-hour naps!

To learn more about the benefits (and potential drawbacks) of napping, visit the National Sleep Foundation's website!