Studies have found different benefits—and detriments—to a nap’s timing, duration and even effect on different people, depending on one’s age and possibly genetics.
“Naps are actually more complicated than we realize,” said David Dinges, a sleep scientist at the University of Pennsylvania’s Perelman School of Medicine.
“You have to be deliberative about when you’re going to nap, how long you’re going to nap and if you’re trying to use the nap relative to work or what you have coming up.”
If you’ve tried taking naps in the afternoon and found yourself feeling groggy after waking, you may just be doing it all wrong. Even if you don’t work in a job where napping is acceptable, there’s a very clear reason why the best naps are the ones that are usually around the half-hour mark. Here’s why.
The video below explains how sleep cycles work, and how power naps—or those naps that do the most to boost cognitive function during the day by taking advantage of the first two phases of your sleep cycle: stage one, where you’re probably “dozing,” or feel relaxed but if someone woke you you probably wouldn’t even notice you’d been asleep, and stage two, where your brain starts to consolidate memories, organize its biological bookshelves, and shuts the brain off from external, non-dangerous stimuli. If you’re the type who says “It takes me 10 minutes just to fall asleep,” that 10 minutes is probably leading you into stage one—after that, you’re in stage two.
The trouble comes in stage three, or the part where we’re sleeping deeply, and waking is difficult. That’s when you start to feel groggy, and hate the idea of getting up. If you hate mornings, you’re probably waking up during this phase. So the key to getting all of the benefits of naps without the drawbacks is to sleep only for about a half-hour, or the time it takes your brain to go through the first two stages, but not enter the third.
Timing is important when you nap. Whether your company is okay with napping in the office or you slink out to your car for a quick snooze during your break, make sure not to sleep too long. Experts also recommend that the ideal time to nap is generally between the hours of 1 p.m. and 4 p.m. Napping later in the day could interfere with nighttime sleep.