Posted by: JanF | April 21, 2011


Today’s post starts with a stifled yawn.

Sleeping has been in the news lately. Sleeping in air traffic control towers. Sleeping in the cab of an 18 wheeler … while it is moving. 😯

The story on the air traffic controllers pointed out that some European countries allow their controllers to take naps on their breaks suggesting that it allows them to wake up refreshed to finish their shifts safely.

That made me wonder about naps and sleeping so I set my Googleators loose.

First, there are a few facts about sleeping that popped up.

Using electronic devices and computers right before bed can mess up your sleep cycles:

… a new poll by the National Sleep Foundation suggests one of the things keeping us up at night may be our smartphones, our laptops, our TVs, all that technology in the bedroom keeping us mentally engaged until later in the evening. […]And those devices may be impacting the chemistry of our brains, too, by exposing to the bright lights of those screens at nighttime, sort of pressing the reset switch on our sleep cycle.

That can lead to sleep deprivation which has some particularly nasty effects. According to Dr. Charles Czeisler of the National Sleep Foundation:

Most Americans report that they don’t get enough sleep at night. They don’t feel refreshed in the morning. And they report a variety of negative outcomes, including adverse effects on mood, adverse effects on family life, social life, school, work, performance.
– 66 percent of drivers under 30 admit to driving drowsy, 50 percent within the past month.
– 250,000 people a day fall asleep at the wheel in the United States. It’s a pervasive problem.
– people become fast and sloppy when they are sleep deprived so that instead of trying to preserve accuracy by slowing down, they’ll keep going just as fast, even though they have – make more mistakes.

How much sleep do we need? It depends.

Most sleep experts recommend seven or eight hours of sleep although there are those who are short sleepers and thrive on 4 to 6 hours. Most of us we would be sleep deprived on that.

One article suggests that sleeping 10 hours may improve physical performance:

A study from researchers at Stanford University finds that extra hours of sleep at night can help improve football players’ performance on drills such as the 40-yard dash and the 20-yard shuttle.

Shift workers have a particularly difficult time:

… people can adapt to overnight work, but it’s pretty hard to do. There’s the problem of the sun not being out at night (at least for most of the world most of the time) and human nature. On their days off, people who work nights tend to switch back to the daytime schedules their friends and families keep. That flip-flopping makes it difficult for the workers to stay alert at night.

And the research does show that napping can help.

Researchers at the University of California, Berkeley have found that naps may help your brain work better later, kind of prepping it for incoming knowledge:

In the study, researchers took two groups of healthy young adults. Each group completed two learning sessions. The difference was that between the first and second sessions, one group got to take a 90-minute nap. Members of the group that got the nap improved in their ability to learn by 10 percent, while the non-napping group did 10 percent worse.

So what is a “good nap“?

If your nap takes you from stage 1 sleep (just drifting off) to stage 2 (brain activity slows), you will wake up feeling energized and more alert. If your nap takes you into stages 3 and 4 (deep sleep), you will not wake easily and will feel groggy and tired. Sleep stage 1 typically lasts about 10 minutes and stage 2 lasts another 10 minutes. That makes the 20-minute nap ideal for most people (your time will vary to some degree, experiment to learn what works best). Naps as short as 1 to 2 minutes could be effective for some people.

And what about a “caffeine nap” (something I had never heard of)?

Some people claim that drinking coffee and then taking an immediate nap works well. The caffeine kicks in somewhere between 10 and 20 minutes, waking them up. They feel extra energy from both the nap and the coffee. Researchers in Japan found that subjects using a caffeine nap rated highest in decreased sleepiness and increased productivity when compared to subjects taking a nap and washing their face, or taking a nap and being exposed to bright lights.

When all is said and done and the Googleators are exhausted and you finish napping for 1 minute or 30 minutes or sleeping for 8.3 hours or 10 hours, here is where we end up:

“Despite us all knowing the sort of subjective benefits of sleep, what may be surprising to the general public is that scientists and doctors do not still have a satisfying answer as to why we sleep — and that, of course, is one-third of our lives.”

So pardon me while I get on with that third of my life and take a late afternoon nap …

(A version of this was originally posted on 04/21/2011 at BPI Campus)