A more recent study from University of Michigan doctoral student Jennifer Goldschmied and colleagues showed that people who got a 60-minute nap in the middle of the day helped them cope better with difficult people, an effect scientifically described as a boosted tolerance for frustration.
Beyond choosing from the 20 minute or 60-90 minute nap menu, there are several science-backed tactics that will help make your naps more productive:
Set an alarm. "Setting an alarm is really helpful for napping," psychologist Janet Kennedy told Huffpost. "It can be hard to fall asleep if you are worried about whether you will wake up at the right time. Setting an alarm takes the pressure off."
Consider a preparatory nap. According to the National Sleep Foundation, taking a nap before you're actually sleepy in preparation for a late night can ward off fatigue.
Use the nap wheel. Mednick has also developed a wheel that will help you schedule a personal time for the slow-wave sleep cross, a perfectly balanced state in which REM and slow-wave sleep are equally proportioned.
Power up with a caffeine-nap combo. This works well, according to Sleep Junkies, "because it takes around 20 minutes for the body to respond to the effects of caffeine. By taking a short nap immediately after consumption, the stimulant effect kicks in just as you are waking up. Not only will you feel revived from your power nap, you'll also have the added benefit of the caffeine boost."
If you still prefer an extra-long nap on the weekend, you can get a scientific high five for that. In a paper published in the August 2019 Heart journal, researchers followed 3,462 Swiss subjects for 5.3 years. They found napping in the daytime once or twice a week lowered an adult's risk of heart problems.
Naps wielded power over potential heart disease and stroke. However, to reap this benefit, the magic number was one or two naps per week. Adding an extra nap in a given week or taking extra-long or very brief naps did not add to or subtract from the benefits. So as long as you take at least one nap per week, you're good.