Many of us find ourselves longing for a nap to help recharge after a late night, early morning or even a heavy lunch. But we’re often hesitant to give in because the following questions leave us scratching our heads: How long should I nap? Will I wake up even groggier? What if my nap makes it impossible to sleep tonight?
We tracked down the answers to all of those questions and then put together a handy cheat sheet for pulling off the ultimate power nap.
The Science Behind Daytime Sleepiness
First let’s consider what may prompt you to feel sleepy during the day. According to neurologist and sleep health expert Dr. Sujay Kansagra, there are two main factors working within your internal clock that determine how sleepy you feel:
- Homeostatic sleep drive: The longer you’re awake, the more chemicals build up in your brain, eventually telling you that it's time to go to sleep.
- Circadian rhythm: This 24-hour sleep-wake system works to keep you awake during certain times of the day, while making you feel sleepy at other times.
When either of these processes becomes misaligned, it causes sleepiness and that nagging midday desire to rest when you would usually be awake.
Timing Is Everything
Scientists have determined that the length of your nap has a direct correlation with how you feel when you wake up. Researchers from NASA determined that “pilots who slept in the cockpit for 26 minutes showed alertness improvements of up to 54% and job-performance improvements of 34%, compared to pilots who didn't nap.” Based on these and similar findings, it looks like the ideal power nap that leaves you waking up feeling rejuvenated should last between 10 and 20 minutes.
Sleeping longer than a half-hour puts you at risk of triggering rapid eye movement (REM) sleep. Meanwhile, a 90-minute nap will move you through an entire sleep cycle, which can leave you feeling more groggy and cranky than when you laid down for a nap in the first place. Entering into a new sleep cycle gives you no added benefits, and it throws off your circadian rhythm.
One final note when it comes to timing: Plan to snooze as early in the afternoon as possible. Pushing your power nap too close to bedtime (anytime after 3 p.m.) will only confuse your body, upsetting its natural rhythms.
How Daytime Naps Affect Nighttime Sleep
Napping is best reserved for times when you’re sleep-deprived from the night prior. In cases like that, a short nap can help you power through your day. Just don’t forget to keep it brief. Making up for lost nighttime sleep with long daytime naps throws off your circadian rhythm, which ends up making you feel more tired.
If you aren’t sleep-deprived but just feeling sluggish, it’s best to skip the afternoon snooze because unnecessary napping can affect your ability to sleep at night. In general, it’s best to have one long, solid stretch of sleep at night versus a couple “pockets” throughout a 24-hour cycle.
Your Cheat Sheet to the Ultimate Power Nap
Before sending you off on your (very quick) voyage to afternoon la la land, remember to keep these rules in mind:
- Don’t snooze for too long. Anything past 20 minutes will send you into deeper sleep, and you’ll feel groggy upon waking.
- When timing your nap, remember “eight is great.” The sweet spot is smack-dab in the middle of your wake cycle: eight hours after waking and eight hours before bedtime.
- Rest your head—literally. Make sure it’s well supported by a pillow, especially if your nap nook consists of only a chair.
- Set an alarm. Knowing you’ll receive a wake-up alert eliminates any anxiety about oversleeping.
- Snap out of sleep quickly. As tempting as it is to hit snooze or delay the inevitable with a few scrolls through your phone, it’s best to immediately get up, refresh with a quick spray of facial mist and expose yourself to natural daylight. That way, your mind and body know it isn’t bedtime.
- It sounds counterintuitive, but consider taking a “coffee nap.” If you enjoy a quick cup immediately before shutting your eyes, the caffeine won’t kick in for 20 or 30 minutes—precisely the time you want to wake up and feel alert, anyway.