Naps for fun and health benefits

We define naps as mid-day sleeping of under an hour. Longer sleep periods during the day are called siestas.

Recent research actually shows that midday naps can reduce the risk of cardiovascular disease, especially for males. A report published in the Annals of Internal Medicine in 2007 reported on a large-scale study of people in Greece. Naps reduced the risk of heart problesm about as much as statin drugs do.

A study in 2006 concluded that regular naps of less than 30 minutes can improve productivity and mental performance. Regular longer naps are associated with higher mortality. The authors felt that regular nappers could get the most out of their naps by "training" the body to awaken after a short nap.

People who napped at least 30 minutes a day, three times a week, were 37 percent less likely to die from heart disease. Occasional nappers had a 12 percent reduction. Although there is always a risk that daytime naps lead to nighttime insomnia, individuals can learn the specific needs and response of their bodies. Many people can nap in the daytime without nighttime problems. A study of seniors in a retirement community found no significant impact of napping.

Between 2 p.m. and 4 p.m., your body naturally experiences a small dip in temperature, signaling the brain to produce the sleep-inducing hormone melatonin. Sleep plays an important, if not wholly understood, part in formation of long term memory. Memories are consolidated during sleep. Recent research found that short naps can be very effective in facilitating learning. Thus the "power nap". It is thought that power nap might accelerate memory consolidation by inducing NREM sleep. More here. And here.

How to take a power nap

What used to be called a catnap is now called a power nap. The word "power" makes it acceptable for working adults who think of themselves as on the top of their game and helps sell napping to people who might otherwise think of it as an activity for small children and old people. Calling is a "power nap" makes it socially acceptable.

Usually the power nap is under 20 minutes, so the brain doesn’t have time to go through all the phases of sleep. Longer naps often leave the person groggy upon waking, but power naps can be refreshing without a sleepy hangover.

Some people take their power nap iat their place of work - at their desk chair for instance. More ambitious nappers have a cot near their office or even go out to their car for a nap. Most do not use alarm clocks.

The Boston Globe published a one-page guide to napping. It's pretty good although for some reason they include a drawing of a monkey in the tree.

Who's napping?

Little kids often nap as part of their regular day. Old people are also stereotypical nappers. In both these cases, age-related sleep patterns can explain part of the predilication. A Pew Reseaech Center survey found that 34% of U.S. adults nap on any given day. Among those past age 80, the percentage was 52%. Men are more like to nap than women and regular exercisers were more likely to nap than sedentary people.

NASA research on napping to help astronauts

Recreational sleep

Sleep Disorders

Dyssomnias

Parsomnias