Sleep, Caffeine, and Coffee Naps

Sleep, Caffeine, and Coffee Naps

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Coffee vs. Napping: Which is Better?

How do those guys who get by on 4 to 5 hours of sleep do it? Maybe we can use caffeine naps to approximate their ability.

I’ve been reading the same rule all my life. You’ve been reading it all your life: “Humans need 7 to 8 hours of sleep a night. Or else!”
It usually doesn’t say “or else,” but it’s kind of implied. If you don’t get 7 or 8 hours of sleep, you’ll flunk Mrs. Weatherbee’s geography exam; you’ll lose the big Peterson account; you’ll kneecap your immune system and develop diabetes and the big C; you’ll hit the gas instead of the brake, end up dead in a lake; or, or, you’ll never know love again, you poor, miserable, sleep-deprived bastard.
If only you could refrain from watching those late-night Frazier reruns on the Hallmark channel and grab a little extra shuteye so you could hit your pre-ordained sleep numbers.
The reason that supposedly hard and fast sleep rule pisses me off is because I don’t – I can’t – sleep for 7 to 8 hours a night. It’s usually around 6 hours. And I can’t help but think, based on how concrete and inarguable that 7-to-8-hour sleep rule seems to be, that I’m somehow shortchanging my health.
But then I think about all the famous people who also have truncated sleep cycles. Former President Obama admitted to sleeping as few as 5 hours a night, and based on former President Trump’s social media habits, it appears the man is like one of those birds that lets half their brain sleep at a time so they can continue to tweet, or in this case, Tweet. Elon Musk, too, apparently only needs about 6 hours to keep his vigorous ego at full throttle.
Martha Stewart? Four hours. Winston Churchill? Five hours. (Of course, he was what’s known as a “biphasic sleeper” since he always completed his sleep cycle by taking a two-hour long nap.) Another English PM, Margaret Thatcher, also reportedly slept just a few hours. Lastly, there’s a mysterious Count Alucard from Romania who’s said to stay up all night.
But are those sleep numbers accurate, or part of the mythology famous people sometimes create for themselves? Thatcher famously had a “lunch is for wimps” image and reflecting that “sleep is for sissies” might have been part of that. It’s not hard to imagine that other famous personalities with equally famous egos might also be cultivating a certain tough-guy mythology.
Science, however, seems to be at least a little more forgiving of their claims as they believe that “short sleeper syndrome” – a condition where certain people can achieve the same level of recuperation as other people but in a shorter time period – actually exists.

What’s Special About These Short Sleepers?
A 2014 study in the aptly named journal, “Sleep,” found that a rare variant of a certain gene – BHLHE41 – is associated with shorter sleep and resistance to sleep deprivation. People with this mutation reduce their total sleep while maintaining their NREM (non-rapid eye movement) sleep, which is one of the three stages of sleep necessary for physical recovery and “memory consolidation.”
A few years later, another group of researchers found a second sleep mutation that also reduced the need for sleep, this one on the ADRB1 gene. However, they estimated that this mutation is also exceedingly rare, with an incidence of 4.028/100,000 (roughly four people out of 100,000).
Unfortunately, there’s no specific test (aside from getting genetic testing for the mutation), but sleep researcher Andrew Coogan of Maynooth University in Ireland says that “…if on the weekend someone’s sleep duration does not get any longer, despite having the opportunity to sleep in, then they may be a true short sleeper.”
Along the same lines, if you need an alarm to wake up, you’ve underslept. Period.
Okay, so we’ve got “regular” 7-to-8-hour sleepers, over-achiever sleepers, vampire sleepers, people probably lying-their-ass off sleepers, bi-phasic sleepers, people who think they can get by with less than 7-8 hours but are sadly deluded, and X-Men mutants who are legitimate short sleepers. We’ve even got people on the opposite end of the sleep spectrum, like Mariah Carey whose diva-ness allegedly requires 15 hours of sleep a night.
So where does someone like me fit in? Like I said, I sleep about 6 hours. I suspect a lot of you might be in the same gently rocking, lullaby boat. Too bad science only pays attention to the 7-to-8-hour sleeper and the incredibly rare outliers who need less than 6. What about the rest of us who fit somewhere in the middle? HEY SCIENCE, WE EXIST!
But am I/you, the less-than-prescribed-8-hour sleeper, slowly chipping away at our health and performance? How about napping? Is it a viable solution for anyone other than septuagenarians and octogenarians who sometimes don’t wake up from said nap? How about caffeine? Is it a viable alternative to napping or possible sleep deprivation in general? And is there some nifty way to combine caffeine and napping to enhance the effects of sleep?
(Okay, I’m teasing you on that last one. Spoiler alert: There does seem to be a way to enhance sleep quality by combining it with caffeine, despite how paradoxical it sounds. More on that below.)
The Science of Napping
I’m not going to drone on about the ill effects of less-than-optimal sleep. I’ll just quote Dr. mc schraefel (lowercase intentional), professor of human performance and T Nation contributor and leave it at that: “If we perform for, say, a week, for an hour less sleep a night than we need, you have the same performance as if we had an illegal blood alcohol level.”
Given that “sobering” assessment, let’s examine the two main ways people try to thwart the innately programmed 7-to-8-hour sleep period. First up are the nappers or “bi-phasic” sleepers, like Churchill. (Let’s adopt that term. “I’m taking a nap” makes you sound like some kind of candy-ass slumber bunny. Instead, command respect by saying, “I’m going to engage in some bi-phasic dormancy.”)
Here’s the trouble with napping, er, bi-phasic dormancy, though: A 2008 survey of almost 11,000 adults found that while most of them would like to have an hour more daily sleep during the day, they wouldn’t accept it if there were “attractive waking alternatives.”
That means that the child in us who wants to stay up just an hour later with mummy and daddy dies hard. I suspect this FOMO mindset is common to people who rely on caffeine to ameliorate the effects of mild sleep deprivation, which is the equivalent of whipping their nervous systems with a riding crop, but hopefully not until our body/horse falls from exhaustion, is shot, and then sent to a dog food factory.
So, let’s compare the last two groups, the nappers and the caffeinators, and see if we can find some similarities or advantages and disadvantages to each.
First, let’s define what we mean by a “nap.” It seems it’s a very fickle thing with its own set of rules. I’m sure you’ve heard all about sleep cycles and REM sleep and non-REM sleep, but napping is one instance when you become physiologically aware of just how much clout those sleep cycles have.
For instance, if you take a nap that’s longer than 20 to 30 minutes, you risk being woken up during a REM phase, and you’re likely to experience “sleep inertia.” This sleep inertia is characterized by grogginess, disorientation, and drowsiness. It’s almost like a mild hangover. It generally lasts between 15 and 60 minutes, but it could last for a couple of hours.
Scientists aren’t exactly sure why sleep inertia occurs, but they think it may have to do with the amino acid adenosine, which plays a pivotal part in sleep and restfulness. When you wake up, adenosine levels should be low (sleep clears adenosine), but sleep inertia could be caused by still-high levels of the amino acid caused by prolonged sleep deprivation.
So, napping can help offset the effects of a reduced night’s sleep, but it generally needs to be kept to just 20 to 30 minutes. Once in a while, though, you need the extra sleep, you need to crash for an hour or two, sleep inertia be damned. That’s fine. Just realize that it might take at least 60 minutes or so to recuperate from the sleep inertia.
Still, regarding naps in general, the child in us dies hard and most of us would rather have a cup of coffee instead and do something more fun or rewarding. There’s also the “wimp factor” mentioned at the beginning of this article. Few men who are positively soppy with testosterone feel comfortable about naps, let alone copping to them.
Lastly, napping can interfere with nighttime sleep, so coffee (at least early in the day) is often a preferred alternative, especially when you’re about to get into a car and make the long drive to Hoboken.
The latter is especially important since a survey conducted by the National Sleep Foundation found that 60% of drivers reported feeling drowsy at the wheel while 20% reported having fallen asleep at the wheel, an occurrence that accounts for 30% of motor vehicle accidents at night.

Caffeine or Napping: Which is Better?
It’ll come as no surprise to you to find out that multiple studies have found that when mildly sleep-deprived subjects ingested caffeine – anywhere from 150 mg. (the amount in a single, “strong” cup of coffee) to 300 mg. – had positive benefits on driving performance, subjective alertness, and mood. Another caffeine study, this one involving medical students, found that the chemical improved their performance on simulated laparoscopies after overnight sleep deprivation (i.e., fewer punctured livers and the like).
It’s much the same with athletic performance in both the well-rested and the sleep deprived. (Obviously, coffee/caffeine works even better as a performance enhancer in those that had a good night’s sleep.) Study after study has found it to increase endurance and even power. No wonder the NCAA bans high doses of caffeine.
(Although it must be said that at least one study found that decaf coffee had the same effects on performance as caffeinated coffee, probably because coffee itself contains a rich brew of polyphenolic chemicals.)
The trouble is, using coffee to take the place of sleep is a little like the One Ring in LOTR – use it for too long a time and you eventually turn into a Gollum-like creature who wants to kill the hobbitses in line in front of him at Starbucks that are preventing him from getting his Iced Caramel Macchiato.
One recent study did, however, throw some shade on the whole caffeine/athletic performance relationship. Iranian researchers recruited nine highly trained male judokas and subjected them to five different sleep/caffeine situations. They found that a 20-minute nap improved repeated sprint performances, while those that were sleep-deprived but ingested a moderate dose of caffeine didn’t show any improvement in performance while also suffering increased muscle damage.
Here’s the surprise, though: That same study found that the group that ingested caffeine before a nap performed the best. It sounds paradoxical, i.e., how the hell can you nap after a cup of coffee? There’s plenty of science to back it up, though.

The Best of Both Worlds – The Coffee Nap
Before you can grasp the concept of the coffee nap, we need to look at how coffee, i.e., caffeine, fights sleep deprivation. It seems it has to do with the amino acid adenosine mentioned above. Adenosine is a byproduct of brain activity, so the longer you’re awake, the more adenosine finds its way to their accommodating receptors and the more you feel tired.
Caffeine, however, is an adenosine “antagonist,” meaning it competes with adenosine for those same receptors. As sleep author Stephen R. Braun writes, “It’s like putting a block of wood under one of the brain’s primary brake pedals.”
So, bright reader that you are, you’re probably thinking, “How ya’ going to take a nap if the caffeine is blocking all those receptors and making you alert?”
Good question, but the caffeine takes about 20 minutes to get to your brain. So, drink a cup of caffeinated coffee and immediately curl up with your banky. The sleep – which is yet to be affected by the caffeine – naturally clears some of the adenosine from the brain, so when you wake up after 15 or 20 minutes, the parking lot opens up – adenosine has largely cleared out and the caffeine that started its journey 20 minutes ago can motor right in. These newly parked caffeine molecules can then get to work revivifying your tired ass.
Several studies have backed up this phenomenon. Researchers at Loughborough University in the UK found that a 15-minute coffee nap led to test subjects committing fewer errors in a driving simulator. (This was true even if they had trouble falling asleep and just laid there for the 15 minutes.)
Similarly, a Japanese study found that people who took a caffeine nap performed better on memory tests than those who just took a nap.
Perhaps most interestingly, there’s evidence that the caffeine nap can thwart the effects of relatively long periods of sleep deprivation. As part of one study, 24 young men were deprived of decent sleep for 24 hours. The 12 that had taken caffeine naps performed roughly the same as the non-sleep-deprived baselines for the entire day.
It’s doubtful, though, that this strategy would continue to work in the long run. You can only thwart biology for so long.
The Take-Home Points
Most people need 7 to 8 hours of sleep a night, but a couple of rare, distinct gene mutations allow a few to get by on 4 to 5 hours a night with no apparent ill effects.
Many people only require 6 to 7 hours a night, but science seems to ignore their existence.
If you deprive yourself of as little as an hour of needed sleep a night for a short time, your performance will be equivalent to someone who’s legally drunk.
Some people overcome short, detrimental sleep periods by practicing “bi-phasic” sleeping, which consists of completing the needed sleep cycle later in the day via a second sleep, which is essentially a long nap.
If you nap longer than 20 to 30 minutes, you run the risk of being woken up during a non-REM sleep phase, which will result in “sleep inertia,” which is a period of grogginess and disorientation. This sleep inertia generally lasts between 15 and 60 minutes, but it can last for a couple of hours.
Caffeine consumption on the order of 150 mg. (i.e., a strong cup of coffee) can partially offset the decline in physical and mental performance caused by mild sleep deprivation.
Taking a “coffee nap” combines the best of both worlds in that it makes you more alert than just a nap or just a cup of coffee. It involves drinking a cup of coffee immediately before taking a 20-to-30-minute nap. The nap partially clears the brain of adenosine, allowing coffee to march in after 20 minutes or so and take up residence in those same receptor sites, making you more alert than you would be otherwise.
The “coffee nap” appears to work even if you have trouble falling asleep during the nap.
Regardless of any or all these strategies, no amount of caffeine can make up for prolonged periods of sleep deprivation.
ReferencesReferences
Alameddine Y et al. Caffeine and Naps as Countermeasures for Sleep Loss, Sleep Deprivation and Disease: Effects on the Body, Brain and Behavior. Springer Science and Business Media. New York, 2014.
Mesas AE et al. Is daytime napping an effective strategy to improve sport-related cognitive and physical performance and reduce fatigue? A systematic review and meta-analysis of randomised controlled trials. Br J Sports Med. 2023 Jan 23;bjsports-2022-106355. PubMed.
Hodgson AB et al. The Metabolic and Performance Effects of Caffeine Compared to Coffee during Endurance Exercise. PLoS One. 2013;8(4):e59561. PubMed.
Horne J et al. Sleep extension versus nap or coffee, within the context of “sleep debt.” J Sleep Res. 2008 Dec;17(4):432-6. PubMed.
Mawer R. How Caffeine Improves Exercise Performance. Healthline. September 10, 2021.
Phelan J. Does short sleep syndrome really exist? LiveScience. January 2023.
Riley B. How Do the Rich Rest: Are Their Sleep Cycles the Secret to Success? CEO Today Magazine. June 30, 2021.
Romdhani M et al. Caffeine Use or Napping to Enhance Repeated Sprint Performance After Partial Sleep Deprivation: Why Not Both? Int. J Sports Med. 2021, May 1;16(5):711-718. PubMed.
Stromberg J. Scientists agree: Coffee naps are better than coffee or naps alone. Vox. April 23, 2015.

I’ve always had the strange ability to go to sleep and pre-set a time I want to wake up without an alarm.
Freaks my wife out completely.

Me too…just like Jack Reacher,

But can you throw virtually any object, regardless of shape, and hit small children in the face?

Kramer was able to do that, too, but when Jerry told him to set his mental alarm clock, it didn’t work because the power went out because Kramer was using his 50,000 BTU heater to heat his hot tub and then Jerry’s regular alarm didn’t work either, causing Jean Paul to be late for the New York City marathon and this time it had nothing to do with the snooze button. So yeah, be careful with mental alarm clocks.

SkyzykS:

But can you throw virtually any object, regardless of shape, and hit small children in the face?

I can absolutely do both of those things.

I too cannot sleep for 8 hours.5-6 is it. No alarm clock needed on most occasions.

Regarding this point, “Along the same lines, if you need an alarm to wake up, you’ve underslept. Period.” I have noticed that on week days (when I’m going to work), I almost always need an alarm, even if I slept 9 hours. On weekends or on vacation, I often wake up early with no need for an alarm. Same thing in the summer, when it’s already warm and sunny early in the morning. I think mentality has a lot to do with it. I don’t think there’s a difference in my gym performance though, and I never have problems with energy throughout the day if I slept 8-9 hours, regardless of whether I needed an alarm (I don’t drink caffeine).

So you’re saying your body’s reluctant to get up when it’s for something you don’t want to do, and eager to get up when the day is yours to do with as you please? Make sense.

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