The Perfect Nap Is A Science


If you’re sleep deprived you can’t learn, perform, or think as well. But, are naps a good thing? The perfect nap is a science based on circadian rhythms.

Let’s look at the science of napping, and how to nap, for the biggest brain benefits!

Louie loves to nap so he was far more enthusiastic about this post than our post about a  new ocean mammal discovery!

Kidding aside, that’s an intriguing post.

Back to naps! The great news is that there are brain benefits to napping!

The Science of Napping_word cloud
The Science of Napping_My cool word cloud!


The Perfect Nap is a Science_Baby louie_get comfortable
Louie is always ready to help with a nap!

ARE NAPS A GOOD THING? (okay, you are savvy, picked up on the subtext and know naps are a good thing, but I want to share why...not to mention the brain benefits)

Ovid thought so:

There is more refreshment and stimulation in a nap, even of the briefest, than all the alcohol ever distilled.” –OVID


Pretty, but not as good as a nap.

Ovid was a poet born in Sulmo, Italy on March 20, 43 BCE. 

His most famous and revered work is “Metamorphoses,” considered a masterpiece alongside the works of Homer and Virgil.

The science of napping_ OVID thought so statue
He looks like he needs a nap.

Have you read Metamorphoses?

Others may disagree that naps are a good thing, such as Rita Rudner’s (ex) stepfathers.

Ms. Rudner reports: My mother was a very tough woman. She buried three husbands and two of them were just napping.

Are naps a good thing_Rita Rudner
Sleep with one eye open


Which brings me to the interesting question: Why do we sleep for 6-9 hours, then stay awake for twice as long?

Most people get their sleep in a single long bout,  for 6-9 hours at night. This is called monophasic sleep.

However, evidence is emerging that we may not have been programmed to sleep in this way.


Are Naps a Good thing?_Louie
Louie is safe from predators!


Think about it.

How would it do for our ancestors to lie down under a tree, or even in a tree, and virtually be unconscious and vulnerable to predators for an 8-9 hour stretch?

In a word, that would have been dangerous.

The perfect nap is a science_ andrew-seaman-unsplash
Sure the cheetahs can sleep but what about us? courtesy Andrew Seeman_Unsplash


Studies show that our brains may have been hard-wired for biphasic sleep.

Defined by the sleep foundation: Biphasic sleep is a sleep pattern in which a person splits their sleep into two main segments per day. 

Are naps a good thing?
Another example of Louie assisting with a nap!

A person or animal may sleep longer at night, and then take a nap during the day. Someone  may also split their nighttime sleep. 

Biphasic Sleep
Earliest written references to biphasic sleep are in Homer’s Odyssey. Yes, more classics!
You don't need to read it but if you want to...Homer's Odyssey
Voluminous evidence points to our ancestors sleeping in 2 phases
Biphasic sleep in pre industrial societes
If you nap regularly, you aren't alone!
A PEW study shows that over 30% of adults in the U.S. nap
Previous slide
Next slide

Researchers had to dig for anthropologic references to sleep patterns. We sure can’t find fossil evidence of sleep patterns!

Skull from shipwreck
This guy isn't talking but he'd probably tell us he should have napped, to avoid crashing his ship.

It’s hypothesized that during the 18th century, progress in urban lighting in Europe & America–fueled by oil from the whaling trade–disrupted the biphasic sleep pattern.

Why are lights disruptive to sleep? Because of our circadian rhythms.

aconitine uses to poison whales
UGH to the whale trade. (More on whales click the photo)
bright street lights disrupt our circadian rhythm
Too bright for proper sleep


For years, researchers have known that living organisms, including humans, have an internal, biological clock that helps them anticipate and adapt to the regular rhythm of the day.

Chronobiology is the study of circadian rhythms. 

Circadian Rhythm
External clock!

Take one, 24-hour period. I starve you. You’re hangry, of course.

What if I take away your water? You’re angry & thirsty.

But if I keep you awake for 24 hours straight, everyone will notice how compromised you are. The results could be dangerous.


Life on Earth is adapted to the rotation of our planet.
The master clock is a group of about 20,000 nerve cells (neurons) that form a structure called the suprachiasmatic nucleus, or SCN.
More on the SCN
The SCN is in the hypothalamus & receives direct input from the eyes.
credit NIGMS
The SCN controls the production of melatonin, a hormone that makes you sleepy.
The SCN receives information about incoming light from the optic nerves, which relay information from the eyes to the brain. When there is less light—for example, at night—the SCN tells the brain to make more melatonin, so you get drowsy.
More light has the opposite effect.
I'm awake and ready to go!
Previous slide
Next slide

Okay so we’ve got light affecting melatonin production via the suprachiasmatic nucleus. It’s not quite that simple, because of adenosine.

The Perfect Nap is a Science_Alex
Light or not, I might be ready for a nap. Why?
Eros Sleeping
One last classic reference to napping. 3's a charm.
Circadian Rhythm Internal clock courtesy Nobel dot com
Rough Circadian Rhythm Diagram courtesy nobel dot com
From the moment you wake up, your brain produces a chemical called adenosine, which is a neurotransmitter that--among other functions-- promotes sleep & suppresses arousal.
Click Here
The longer you're awake, the more adenosine builds up, like steam in a pressure cooker.
Adenosine & sleep quality
The time varies but when adenosine has built to its threshold, you must sleep to release it.
Adenosine receptor research
Previous slide
Next slide


In 2017, researchers Jeffrey C. Hall, Michael Rosbash, and Michael W. Young won the prestigious Nobel Prize for their circadian rhythms research
By studying fruit flies, which have a very similar genetic makeup to humans, they isolated a gene that controls our normal daily biological rhythm.
Nobel Prize Press Release


Humans often experience a biological drop in alertness in the afternoon.
Study on activity peaks
courtesy Iowa Digital Library
It’s a natural part of human circadian rhythm, you’re going to be intensely sleepy twice per day.
Remember the biphasic sleep evidence? You can't stop it. None of us can!
Blame the protein (s) these guys isolated.
This protein accumulates in cells overnight, then degrades during the day. This process can affect when you sleep, how sharply your brain functions, and more.
PER protein research
Previous slide
Next slide

What can we do about this drop in cognitive performance & concentration?

5 hour energy shots? Coffee? (for the perfect cup of joe, I’ve got a great post here)


We can take a nap!

2008 study showed that naps are better than caffeine when it comes to verbal memory, motor skills, and perceptual learning.  

The Science of Napping_Louie is all about naps
Did you say nap time?


Caffeine causes most of its biological effects via antagonizing all types of adenosine receptors. 

I would never bash caffeine or chocolate. I love both caffeine & chocolate but this post is about the science of napping!


Make the perfect cup of coffee in one step
For a post about coffee, click the photo!

What if we combine caffeine with our nap? How you ask? 

Daniel Pink suggests this in his book, WHEN. Drink 200 mg of caffeine right before your 25-minute nap!

napping owl
Okay, this owlet didn't have a cup of coffee...

You’ll wake up without sleep inertia, right when your caffeine is kicking in! 

kevin napping
Yes, I set my timer


Are Naps a Good thing? Not just for kids_5 boys
We don't care about napping for the biggest brain benefits!

Those boys are silly. Of course we care about brain benefits!

Naps offer many benefits for your brain & for your body.
Nap research in healthy adults
The human brain can only store so much information before it needs to recalibrate. Naps improve cognition!
Naps + cognitive performance
Without sleep & the recalibration that goes on during sleep, memories are in danger of being lost!
Memory retention w napping
Naps & learning
BP study
We don't need that extra cortisol!
Other ways to decrease stress here
shifting you towards positivity!
Another nap study
Ask anyone who's dealt with toddlers! Tired = unreasonable
Naps nurture young brains
Previous slide
Next slide


NASA’s extensive research showed that naps will fully restore cognitive function at the same rate as a full night’s sleep!
Helix Nebula in Infrared
NASA found naps as short as 26 minutes improved task performance by 34%...
Naps & task performance
...And naps provide a greater than 50% increase in overall alertness!
NASA study on naps
NASA suggest taking power naps between 10 & 20 minutes.
Preferably between 1 and 4 PM.
1-4 PM is the sweet spot
Those who regularly nap seem to show greater benefits than those who rarely nap.
regular napping benefits v occasional napping
A 2006 study in Annals of Emergency Medicine observed physicians who napped at 3 a.m., for an average of 25 minutes, showed improved cognitive & psychomotor performance over their sleepless counterparts.
Naps & ER staff
I don't know about you, but I want my doctor to take a nap!
Previous slide
Next slide


According to NASA’s extensive research, the ideal nap is 26 minutes or shorter.  Even ten minutes affords our brain great benefits.

Longer naps are associated with a loss of productivity and sleep inertia. (a period of reduced performance upon awakening from sleep.) Inertia is why you feel groggy after a long nap!

How about a half hour nap? 60 minutes? 90 minutes?

The benefits that come from napping correlate with what occurs during the 4 human stages of sleep.

Chart: 4 Stages of Sleep
Chart: 4 Stages of Sleep
In a 2016 study published in the journal Sleep, researchers found that snoozing for 10 minutes can immediately increase alertness and boost cognitive performance for as long as three hours.
10 minute nap research
After just five minutes of sleep, we enter stage 2.
In stage 2, the brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles.
Sleep spindles are most prevalent in stage 2
They are thought to play a role in brain plasticity, or the process of learning and integrating new memories.
Think of sleep spindles as cementing in place what you just learned or experienced.
Stage 2 sleep can last for 10-25 minutes during the first sleep cycle
Emphasis on 1st sleep cycle aka what happens when we nap.
Stage 3 sleep is also known as deep sleep
Experts believe that this stage is critical to restorative sleep, allowing for bodily recovery and growth. It may also bolster the immune system and other key bodily processes.
Stage 3 sleep is important but deep, so if you enter S3 during your nap, you may experience sleep inertia!
Meaning you wake up groggy!
This tiger probably naps well past the half hour mark!
When we sleep at night the brain cycles through all 4 stages in a pattern lasting 90-120 minutes.
Though a 90-minute nap is usually too long, that’s not necessarily the case if your sleep was severely disrupted the night before!
Sleep medicine study on nap lengths
Who's got time to take a 90 minute nap?
I do!
Previous slide
Next slide


Speaking of disrupted sleep, napping isn’t for everyone. If you have trouble falling asleep at night, insomnia, or staying asleep at night, napping could interfere. Here’s a link for the national sleep foundation if you’d like a few tips on combating insomnia.

Nap for the biggest brain benefits_AK_Alex
That bed looks a little small...

In brief, try lowering the lights in the evening, don’t eat after 7, no caffeine or naps (!) after 3, and no screens in your bedroom will help nudge your circadian rhythms. Using a happy light in the morning or sitting in a bright room upon awakening is another way to trick your body into better rest at night & awakeness during the day.

bright lights during the day help circadian rhythms
This is not my kitchen
low lights at night help circadian rhythm
This is not my family room, either. (I love the lights over the plants.)


So the next time you’re feeling drowsy, you could pour a cup of coffee or black tea, exercise, or eat some dark chocolate! Not altogether bad options.

Remember that there is another cozier alternative, one that has many cognitive, emotional, & performance benefits.


Nap for the Biggest Brain Benefits_Louie
Louie is recharging his brain!


Think about it! If you need to have a speeding ticket expunged or have an important job interview, don’t schedule it late morning or the end of the day, when others’ have a drop in their circadian rhythm!

Strict judge
Nap? I took one during lunch!


This post took me far longer than usual because I had to take frequent nap breaks! 

Do you recharge your brain by napping?  


I do the research so you don't have to!


Inline Feedbacks
View all comments
Unwanted Life
December 13, 2021 7:05 am

I wish I could sleep 6-9 hours a night, I don’t think I’ve managed that since being in primary school. I tend to only nap for a few minutes, but that’s normally because I start blacking out without warning. Taking a short nap stops that

December 13, 2021 7:21 am

How interesting that a 25-minute nap can have such benefits. I like meditation but this is a quick easy way to recharge. Thanks!

December 13, 2021 8:12 am

For years I’ve taken a 10 to 15 minute nap at lunchtime. You’re right it really improves your alertness. Now that I’m retired a good hour nap seems most beneficial. Loved the post. Mike

December 13, 2021 8:40 am

Great post! As a big fan of napping, glad to know it does the brain good 🙂

Tiffany McCullough - Metaphysical Mama
December 13, 2021 10:33 am

I love naps! I didn’t realize that even a 10 minute nap could have such benefits. Thanks for sharing this!

Amy Laundrie
December 13, 2021 10:33 am

I love a 20 minute afternoon nap on the living room couch where the sun streams in. Heaven.

December 13, 2021 1:09 pm

This is such a great post, I found this really interesting! I try to get 6-9 hours a nigh as I don’t survive very well with lack of sleep ahaha. I have to have a nap in the afternoon! Xo

Elle –

Marian Grudko
Marian Grudko
December 13, 2021 2:01 pm

Hi Sue! I’m not much of a napper, but here’s a phenomenon you might be able to shed some light on for me: When I’m faced with a difficult task of, say, editing and organizing a book manuscript, and there are so many options and choices to make, I instantly get so sleepy I could fall over. Any time of day. Your thoughts? Thanks! And thanks for always great posts.

Mummy Conquering Anxiety
Mummy Conquering Anxiety
December 13, 2021 3:29 pm

As always, I love your posts. So informative and entertaining to read.

I love a nap. With a little one, I never get enough sleep, so a nap in the afternoon is needed!

December 13, 2021 5:05 pm

This is such great information about napping! I usually have a hard time napping, but sometimes, it’s definitely necessary!

December 13, 2021 5:12 pm

I’ve never been able to nap. I’m quite a poor sleeper and struggle to go to sleep during the day!

Corinne x

Eri Tz
December 14, 2021 3:14 am

I love sleeping and of course I do love taking naps. This post gave me more reasons to continue doing so. I use a fitness tracker and have noticed that ever 20-30 minutes nap has a major effect on my energy levels and my ability to stay consentrated. Really informative post!

Jenny in Neverland
December 14, 2021 5:25 am

Love this post! I absolutely loveeee a good afternoon nap because I always experience a drop of energy in the afternoon at around 2pm. I tend to go for a nap instead of coffee – I actually feel like coffee doesn’t do an awful lot for me!

December 14, 2021 6:38 am

I’m not much of a napper but interesting to read the benefits. Thanks for sharing!

Fransic verso
Fransic verso
December 14, 2021 11:32 am

I like naps but I stopped taking them because I’m almost all day busy. Great post about napping.

Jodie | That Happy Reader
Jodie | That Happy Reader
December 14, 2021 6:51 pm

This is so interesting! I love nothing more than having a 15-20 minute power nap when my body requires it. You can certainly see the chaos on sleep patterns that jet lag produces. When on vacation 8 or 9 time zones away I have a hard time falling asleep only doing so when everyone else is getting up! Thanks for sharing.

Jodie | That Happy Reader
Jodie | That Happy Reader
Reply to  Susan Berk Koch
December 15, 2021 4:15 pm

I travel from Vancouver to Europe yearly (pre-pandemic). My hubby sleeps without difficulty and feels great. I take 3 or 4 days to be able to get. 7 hour sleep.

I'm All Booked Up YA
I'm All Booked Up YA
December 15, 2021 7:49 am

This is a really interesting post for someone like me who struggles to sleep through the nigh. I guess my dog has the right idea!

Molly @ Transatlantic Notes
December 15, 2021 8:45 am

I’m definitely a fan of a power nap here and there; they pretty much saved my sanity over the last couple of years when sleep had bee alluding me — thanks for all this info, it’s fascinating!

December 16, 2021 6:41 am

This is a really interesting post! I hate napping and it never makes me feel any better- unless I’m ill I try to avoid it. This is really interesting though and I enjoyed finding out more about the science behind it x

Reply to  Susan Berk Koch
December 16, 2021 7:03 am

Yes it could be that, and I found this post very insightful- who knows, maybe it will help me properly nap in the future!

Reply to  Susan Berk Koch
December 16, 2021 7:06 am

I will do x

December 16, 2021 9:03 pm

I’ve never been a good napper (or sleeper in general). I’ll try some of these tricks.

Baby Boomer Super Saver
December 17, 2021 1:30 am

My husband takes naps every day. He always has. Unfortunately, I have never been one to nap, unless I’m completely exhausted. I wish I could nap, because I’m a bit of a night owl and rarely get enough sleep.

Isa A
Isa A
December 17, 2021 1:01 pm

Ok this time your post rhythm was a bit different. Good ofcourse but different. Didn’t know the phases names. I find hard to sleep and naps are impossible in my case haha. But I learnt l. Thanks for sime good info. Xx
Isa A. Blogger

Kelly Diane
December 23, 2021 3:47 am

This was really interesting. My sleep pattern has been awful lately. I’ve only been sleeping about 3 hours a night but have been benefiting from a couple of naps in the daytime.

February 2, 2022 3:33 pm

Fascinating! I was never a napper, but learned to be one whilst pregnant. Freaking love to take a nap now.

Hannah Peters
April 19, 2022 5:56 am

Thank you, Susan! Your posts are so interesting and informative! By the way, I’ve heard that swimming in salt water makes people sleep better? Is that really the case?
All the best!

May 27, 2022 3:31 am

I heard that you actually need a 15-30 minutes nap break in the middle of the day to boost your energy. I tried several times and it surely works!

Susan Berk Koch author

My New Book!

Be the best-informed reader!

Make Sense of Science is my email newsletter where I share information about future science, new tech developments, as well as tools and resources for STEM at home. It arrives every two weeks and you’ll only hear from me. (And Louie)


Be the smartest person on your block!

Enter your email & I’ll share news about future science, STEM activities, and the best books.

And more Louie!

Louie says please subscribe to our science blog

Be the Best Informed!

I’ll make sense of science, share news about new tech, science advancements, and more. You’ll only hear from me and only twice a month. 

Louie loves STEM at home activities

Be the smartest person!

I’ll share news about future science, new species, show you how to do science at home with your kids, find the best books and more. You’ll only hear from me and only twice a month, tops.

Louie will be so happy!

Don’t miss out on More Cool Science! Subscribe for twice monthly articles. Thanks so much.