How to Nap and Not Wake Up Groggy

The elusive glory of the power nap has evaded fatigued students for centuries. Too frequently, you either wake up feeling groggy and worse than you did before the nap, or you oversleep, and that 20-minute nap becomes a 2-hour nap.

The struggle is real. As a former med student, plastic surgery resident, and current business owner, I’m quite familiar with sleep deprivation and the art of napping. Let’s get straight to it.

Understanding the Sleep Cycle

First, the key to understanding napping is familiarizing yourself with the science of the sleep cycle.

The groggy feeling you experience after a nap is called sleep inertia, and it’s linked to being woken during the deeper stages of sleep. It goes beyond feeling drowsy, causing disorientation and limiting your motor dexterity.

For surgeons, that’s a big no-no. Power naps, however, exploit the lighter stages of sleep, specifically stages 1 and 2.

When you’re awake, your brain activity is characterized by beta waves, which are high in frequency, low in amplitude, and more desynchronous than other wave types. When relaxing yet still awake, such as during meditation, our brain waves slow down, increase in amplitude, and become more synchronous. These are known as alpha waves.

Stages 1 and 2 of sleep are characterized by theta waves, which are even slower in frequency and higher in amplitude compared to alpha waves.  In stage 2, theta waves are interspersed by sleep spindles and K complexes.

If you wake up during stages 1 or 2, you’re much less likely to experience sleep inertia. Longer naps subject you to the delta waves of stages 3 and 4. These are the slowest and highest amplitude brain waves. This is the deepest part of sleep and is the most difficult stage to wake from.

During rapid eye movement (REM) sleep, the brain exhibits increased activity, characterized by alpha, beta, and desynchronized waves, similar to the state of wakefulness. This is the state where dreaming occurs. While deeper stages of sleep and REM are considered more restorative, entering these states during naps does not yield the same benefits.

With this understanding of the sleep cycle, it makes sense why we need to keep power naps short. Napping for too long can lead to deeper stages of sleep and cause sleep inertia.

I recommend experimenting with the duration that suits you best. For me, I’ve found that 15 minutes is the sweet spot, and yours will likely be similar as well.

Start in the range between 10 and 20 minutes and experiment from there. Twenty minutes is enough to transition into stage 2 sleep, which has been linked to improvements in memory and creativity.

Crossing past 20 to 25 minutes is dangerous territory. Not only are you more likely to wake up feeling groggy, but you’re also much harder to wake up, thus increasing the chances that your power nap will become a 3-hour slumber.

Now, let’s look at four concerns you may have and how to address each one.

Concern 1: I Can’t Fall Asleep That Fast!

A common concern with power napping is that you don’t have enough time to fall asleep. I have two recommendations for this.

First, invest in some proper sleep gear. Seriously, I bought an excellent sleep mask and earplug combo for only $10, and I’ve never napped better.

And not just a regular sleep mask, but a contoured one that keeps the material off of your eyes. It’s actually a total game-changer. By addressing external factors, such as ambient noise and light, you can create an ideal sleeping environment, allowing your brain to relax more easily into a power nap.

Second, don’t worry about “falling asleep.” Simply getting into bed with your sleep mask and earplugs and relaxing can help calm your mind. That’s enough to get several benefits.

My favorite naps are the ones where I feel like I haven’t even fallen asleep. I get up a couple of minutes before my alarm goes off, feeling energized and ready to tackle the rest of the day.

Over time, you will condition yourself to associate the sleep mask and earplugs with nap time, and you’ll find yourself falling asleep faster than ever. You may need to adjust your power nap duration at this point, as you may be falling into a deeper sleep more quickly.

I now personally go closer to 12 or 13 minutes since the sleep mask and earplugs are so effective.

Concern 2: Oversleeping

The next concern is oversleeping. I’m all too familiar with this. When you’re sleep-deprived, this is particularly dangerous, as you’re even more tempted to hit snooze.

To address this, you must minimize the chances of you hitting snooze. Don’t sleep with your phone or alarm right next to your bed. It’s too easy to hit silence, and the next thing you know, it’s three hours later.

Rather, place your alarm on the other end of the room so that you have to get up to turn it off.  My tendency to oversleep and hit snooze after a rough few days in the hospital was cured by this simple trick. While snoozing in the mornings isn’t a good habit, snoozing during a power nap is a much worse idea.

Concern 3: I Won’t Be Able to Sleep at Night

This is a completely valid concern, and it is best addressed by being mindful of the time you take your nap.

If you take your nap later in the day, the amount of sleep debt required for natural sleep onset that night may be disrupted. For that reason, I recommend limiting your naps to no later than 3 pm.

This, however, will depend on multiple factors, including the specific time you go to sleep. If you’re okay with sleeping later at night, then you can nap a little later in the day. If, however, you intend to sleep early, then stop napping even earlier than 3 pm.

I’ve found that when I’m post-call from the hospital or in other periods of sleep deprivation, I can get away with naps later in the day without much detrimental effect on my sleep later that night. This is because the overall sleep debt is still quite significant.

Concern 4: I Still Wake Up Tired

If you still aren’t feeling as awake and alert as you would like, I have two recommendations.

First, check out coffee naps—they work wonders.

The idea is simple. Drink a cup of coffee or take a caffeine pill, then start your power nap. By the time you wake up, the caffeine has been absorbed by your small intestine, entered your bloodstream, circulated, and begun working its magic.

More specifically, adenosine from consumed ATP builds up in your brain over the course of the day and is one of the factors inducing fatigue. Caffeine competitively inhibits this molecule, meaning it competes for the same receptors. When caffeine blocks the adenosine receptor, you become more alert.

Second, critically examine your sleep at night.

If you’re sleep-deprived, it’s likely due to being inefficient during the day, which results in insufficient time for sleep. If you’re getting enough sleep but still feel fatigued, it could be due to a variety of factors.

A great place to start is by improving the quality of your sleep to feel more refreshed. Six hours of good-quality sleep feels WAY different than six hours of poor-quality sleep.

For more on the science and tips on how to drink coffee effectively, check out my guide on How to Cycle Caffeine Correctly.