Monday, December 3, 2012

The Rules of Naps: Sleep Cycles


The best length of time for a "cat nap," or power nap, is less than 30 minutes.
The best length of time for a "cat nap," or power nap, is less than 30 minutes.
Image: Shutterstock
I’ll admit it: I’m a lover of naps. Sometimes days seem to stretch on forever, and whether it’s because I didn’t get enough sleep the night before or I’ve just had a particularly tiring day, sometimes a midday shuteye session is just what I need to get going again.

But naps can be dangerous, too. Many of us have strayed into the three and four hour range, and while that can be helpful, it’s not exactly conducive to getting things done. The best length of time for a “power” nap is actually less than thirty minutes.

There are three main stages of the sleep cycle. Stages one and two are considered “light” sleeping, and occur within 10-30 minutes. Slow eye movement begins in stage one, as you start drifting off. When you go into stage two, your brain starts inhibiting processing, ignoring outside stimuli, and consolidating memories.

Stage 3 REM sleep begins after 30 minutes.
Stage 3 REM sleep begins after 30 minutes.
Image: Shutterstock
Waking up from stage one sleep often feels as though you didn’t even sleep at all. Waking up from stage two, in contrast, often gives people a boost in productivity and cognitive function, enhanced memory and creativity, and helps them feel more awake and less tired.

Stage three, which occurs after thirty minutes, is considered “deep” sleep, and is when rapid eye movement (REM) begins. Here is where most dreams begin and your body starts slowing down for long-term rest. Waking from this deep stage of sleep causes what is called sleep inertia. Motor dexterity goes down, while grogginess and the desire for sleep increases.

In order to be helpful, not hurtful, naps should be limited to about 25 minutes during the day. Taking a nap can be rejuvenating and increase productivity, keeping you from dragging through the rest of your day. In fact, in Japan, some nap salons have even opened up, giving sleepy workers a chance to get a little shuteye on a daybed before returning to work.


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