A Nap for Every Purpose
Duration and timing are important
A nap is a nap is a nap. Ummm, No. A lot of research has gone into napping since sleep knowledge has advanced.
There are now nap strategies for different purposes and here is a summary of some of them.
Naps during the afternoon can restore alertness and improve performance and learning. Naps before and during night shifts can have similar benefits to daytime naps and can reduce musculoskeletal pain. Night shift naps combined with caffeine are the most effective.
Long naps can interfere with night-time sleep, affecting the ability to fall asleep and stay asleep. Frequent long duration naps are associated with higher morbidity and mortality, including more daytime sleepiness, more pain and fatigue, increased body mass index and waist circumference, higher risk of falls in the elderly, and higher risk of developing diabetes. However, people who nap short periods two or three times a week have a 37% lower chance of heart attack. A routine schedule is important. Because napping affects night-time sleep, we can balance the two if there is regularity.
Even occaisional naps are beneficial to the immune system, expecially after a night of poor sleep.
Short naps improve fatigue, vigor, and cognitive performance. Between 2:00 and 3:00 PM is the sweet spot for a nap.
Generally, naps should be less than 30 minutes or more than 90 minutes. Less than 30 and you probably won’t go into deep sleep and therefore avoid sleep inertia and more than 90 should give you a complete cycle with both slow wave and REM sleep stages.
Here are some guidelines for successful daytime napping duration
10 minutes naps produce immediate results lasting about two hours.
20 minutes naps produce about the same results as a 10 minute nap but with a 30 minute delay.
30 minutes and longer naps can cause loss of alertness and productivity and create sleep inertia as well as interfere with night-time sleep.
60 to 90 minutes naps within four hours of the study or training can yield the benefits equal to eight hours of sleep.
Napping excess remember that long and frequent naps interfere with night-time sleep and the resulting poor sleep leads to pressure to nap more.