So you missed out on a good night’s sleep. Thanks to a little caffeine boost and an energizing breakfast, everything seems fine in the morning — but come afternoon, you’re feeling groggy and braindead. Looks like this calls for a nap. But how long of a nap should you take, exactly? The length of your nap makes a big difference, both in how alert you feel once you wake up and in your ability to sleep later that night. And while you might think that the more sleep you can squeeze into your day the better, that couldn’t be further from the truth.
According to Dr. Sujay Kansagra, the director of the Duke Pediatric Neurology Sleep Medicine Program, the ideal afternoon nap should be 20 to 30 minutes long. “Taking a 20- to 30-minute nap can help combat grogginess and boost mood and energy,” Kansagra told The Active Times in an email. A study published in the journal Clinical Neurophysiology showed that a 20-minute nap, also known as a “power nap,” can boost your mood and productivity for hours afterward.
But if you let your nap stretch on for too long, you can end up doing more harm than good — disrupting your circadian rhythm and waking from your nap feeling even sleepier. “It is important to time your nap appropriately to avoid entering deeper sleep cycles,” Kansagra added. “When your body enters deeper stages of sleep, or even completes a 90-minute sleep cycle in a longer nap, you are likely to feel more tired afterwards rather than refreshed.” The other effects of sleep deprivation may also start to feel more severe.
A nap that runs too long can also end up messing with your sleep that night. “Your sleep stage is likely to be altered,” he said. “This could make it harder for you to fall asleep at night.” And if you try to combat that extra grogginess with yet another cup of coffee or another caffeine source, this could disrupt your circadian rhythm even further. There’s a reason they say you shouldn’t drink coffee after 4 p.m.
A short 20- to 30-minute snooze, on the other hand, won’t have that detrimental effect. No matter how tired you feel, taking a long nap today isn’t worth messing up your sleep schedule tomorrow. You could get caught in a vicious cycle of staying up late and relying on naps during the day, keeping you from ever getting the hours of sleep doctors say you really need.