Cover image for Let's talk about sleep.

Let's talk about sleep.

laszlolm profile image Laszlo L Mari ・5 min read

⚠️ Warning ⚠️: This article will be controversial and may contain information biased towards my point-of-view.

Now that we got that out of the way I would like to talk about sleep. Not just sleep, but about the way people talk about it and about the studies that come up with magic numbers based on massive amounts of people with entirely different backgrounds (physically, mentally, daily routine-wise).

Recently I've seen many articles popping up about sleeping habits, the way humans should sleep, the magic number of how many hours you need and the way you should rest together with hundreds of gadgets or apps that will help you fall asleep and wake up refreshed.

How do you know how much sleep you need?

Well, not from studies focusing on other people. Sleep is one of the most mysterious things we do, and some people spend half of their precious 24 hours on it because they don't understand how it works.

Almost all studies take subjects from various backgrounds and compose an average, but when publishing results, most people skip over these details. A scientist can make an experiment turn in their favor in countless ways. Look at this, this or this to only mention a few. What's even worse is that most people (I would say 80%, but this is a vague estimate) only read news articles about the studies, that are further biased, sponsored, the author might not understand what they talk about, or it's generally not precise enough to draw any logical conclusion.

So now we have a fantastic and extremely abstract topic called sleep. News sites connected sleeping less than 7.5 hours with Alzheimers, cancer and so many different things. The problem is that the patients might have had various factors in their life influencing the development of such disease. For example a recent study found that the environment you grow up in contributes to later developing Alzheimer's. Since the closest you can get to isolated subjects are rats and the brain of rats is still a lot different from humans we can't tell if sleep causes these issues or something else.

Yes, some facts are tough to argue with. The REM and deep sleep states for memory and regeneration have been monitored with MRIs and a bunch of other experiments/machines many times. On the other hand, you can't track how much sleep someone needs generally. The best effort scientists made was measuring brain output (completing creative or difficult tasks) when subjects slept well and when they slept in wrong ways, but this is an extremely short-term conclusion (usually subjects have been called in for only 2 days), and scientists didn't measure what they ate, worked out and so on for weeks before. Even the period between experiments might change results or just that the subject is not in their home, but in a hospital or an unfriendly environment. I am sure I would need a bit more time to fall asleep if I was in an uncomfortable hospital bed.

7.5 hours

This is the magic number. If people sleep above this, they will be healthy and will live a full life, if you sleep under you die of cancer, right?

I don't believe in magic numbers drawn from vague long-term conclusions. For example, I usually wake up after 4 hours of sleep and feel more refreshed, than when my alarm wakes me up after 9. (This is almost every day, by the way, my body kicks me out of bed, and except taking a nap midday I can't really do anything about it).

The way I tested how much sleep I need was by A/B testing the hell out of it for years. It's not a short journey.
Successful businesses A/B test lots of things. Your body unconsciously A/B tests food by creating cravings, you A/B test products or tools when switching between them back and forth for specific tasks, but only very few people A/B test sleep. Instead, they set the alarm for 7.5 hours from now and wake up hoping they will be happy and healthy afterward.

I am not saying you should sleep for 4 hours. I have seen people feeling the worst all day because they tried my methods. In fact, I'm the only one I know who can sustain 2-4 hours of sleep without almost any caffeine intake combined with an "unhealthy" diet (I eat lots of meat, barely any vegetables and some sides. Minimal sugar and close to no caffeine). It works for me, but it likely won't for you.

If you need to rely on caffeine in the morning your body is trying to tell you it's exhausted or that you've built an addiction. If you are yawning your body is saying it's tired and you should go to sleep. There is no shame in napping midday. I often get myself up to speed with a 30-minute quick nap, even if my day is packed with things to do.

What's the point of this article?

People, don't rely on vague scientific facts. Experiment with your own body. If you know your body and mind, you will be able to control your life more than anyone else around you and don't try to fit other people's routines on yours.
A/B test routines as aggressively as you would test your product's features.

Make sure you minimize the external differences between the preparation for tests. This can mean eating the same meal, exercising the same amount, working the same hours and countless other factors depending on your life.

This piece of article is my opinion, and I hope you will take it with a grain of salt. Please validate any point I made and don't fall into the trap of believing another stranger telling you what to do.
One of the main reasons I wrote this article is to send it to people telling me how I should sleep or not sleep and to help people who follow the latest trends of minimal sleep (Silicon Valley, I'm looking at you) rethink their choices. No one knows what effect throwing your body out of balance might have on you. No one, but you in 20 years and until time travel is discovered you might be doing permanent damage to your body by sleeping too much or too little compared to what's natural. If you move to another city or another place you need to redo all of your tests and maybe you should record data points densely to see what fits you best.

Take care of your body, your mind and remember that your body knows itself best, not someone on another continent.

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Nice article, very interesting!

I don't think I can add much value to this since I never quite understood my own sleeping habits but I can totally relate with the idea that there are no absolute rules about sleep (well, excepted the fact that it is needed, unfortunately for our schedules 😀).

Generally, I think the most important thing when it comes to sleep is not the duration (hence why any "magic number" is bulls*** IMHO) but the quality (meaning: 4h of good sleep are better than 8h of "bad" sleep). And I believe sleeping too much affects the quality, so obviously, oversleeping won't compensate the lack of quality. Now the thing is: what is good sleep? That's where it gets complicated because sleep quality is affected by literally everything:

  • You are too rested? Or too rested? -> bad sleep.
  • It's too hot? Or too cold? -> bad sleep.
  • You'd rather sleep alone? Or with someone? -> bad sleep.
  • You are depressed? -> bad sleep.
  • You ate too much? Or too little? -> bad sleep.

... and so on for a lot of various factors and no one is affected in the same way by a specific factor. The two best examples I can find are screens and caffeine. Some people will have trouble sleeping if they used a screen before going too bed, some others (like me) will literally fall asleep every night looking at a screen. Some people won't sleep at night if they had a cup of coffee after 4:00pm, some other will fall asleep half an hour after an energy drink (fun fact: a friend of mine once told me he'd sleep a lot better when drinking an energy drink shortly before going to bed...).

Anyway, aside from endless examples my point is: what makes sleep "good sleep" is different for anyone and depends on a lot of things and that's what people should experiment with rather than with sleep itself (on which you have very little direct control anyway, aside from duration)).

Also, I believe consistency is important too: the human body can adapt to a lot of things but it's a creature of habit, so trying to sleep the same amount of time every night and at the same time frame is most likely quite beneficial.


I agree with most of the points you mentioned.
For me hot or cold doesn't make any difference, just as when I sleep. I used to travel a lot and hop continents so my body kinda got in a state where any sleep anytime is possible. I've heard the same happen to many successful CEOs I know. They can sleep anywhere, anytime with anyone.

Screens also don't make a difference for me, they actually dry my eyes when there is dark around and make me fall asleep faster.

I found physical exercise to contribute a lot to my energy levels. Not overworking myself, but running a constant amount of 10km or swimming an hour makes a huge difference.


About 6 hours personally, but its all about when I wake up for me.

I can go to bed at 6am, wake up at midday and be fresh as a daisy.

Go to bed at midnight and I will stare blankly at you if you speak to me before my first coffee, even if I sleep until 8am.

Not a morning person :)


Completely plausible conversation:

coworker: "Morning! How are you?"
me: "Morning. Coffee."


Pushes cheery co-worker standing between me and the kettle out of the way

I am that cheery "got up at 4:30am and don't drink caffeine" person. HA! Don't worry, I understand when you push me out of the way <3


I tried the "superman sleep schedule" that is 15 minutes every 4 hours. Tried it for a few weeks in college. I can say it absolutely works. It is also completely impractical.

A few years back (single at the time) I got into the habit of sleeping 5pm-8pm then 3am-7am. Worked really well for me until I met my wife. Then, again, became impractical.

Jamming all my sleep into one nightly chunk has always been a challenge for me.


I agree. I also think that quality of sleep plays a significant role. I've had mornings where I thought I would feel sluggish and lethargic for the rest of the day because I only slept 3 hours that night before, and yet ended up feeling the best. Compare that with 10 hours of sleep, where I'd have headaches and feel like I only slept 1 hour throughout the following day. I can never find that sweet spot.


For better or worse, I inherited the "no sleep" thing from my father's side of the family. In general, it's difficult for me to sleep more than 4-5 hours at a stretch. Only exceptions being if I've gone multiple days without sleep, if I've been deprived of 4 hours of sleep for more than a couple days, if I'm ill or in major pain, or if I've medicated. My dad and his dad were both the same way.

Then again, my sleep patterns would tend to qualify as "atypical". Basically, unless in the middle of an anxiety attack or other "too many thoughts" condition, I usually fall asleep within a couple minutes of laying down. Doesn't even matter where: as a kid it could be as "weird" a place as the crook of a tall tree on a windy spring day. In addition to my "fall-fast"/"fall-anywhere" sleep patterns, my dreams usually start even before it feels like I've fully settled in to sleep. My brain seems to make the most of its down time so that it doesn't need a lot of time to get the same degree of recharge that others require double the time for.

The real thing that told me that "4-5 hours is normal for me" was when I'd had apnea-correcting surgery in my late 20s. The apnea had caused my sleep-need to go beyond 14hrs/day. The day after the surgery (and throughout the post pain-meds recovery-period), my sleep-need dropped back to the pre-apnea 4-5 hours of sleep.

Apnea's no joke. It eventually got to the point that, even with such protracted sleep-periods, I was still so sleepy that I had become narcoleptic from it. The narcolepsy resulted in a couple car accidents and several more near-misses. It was the devolution to driving problems that ultimately led to the surgery (CPAP exacerbated rather than alleviated the problem). Fortunately, and, far more frequently, the apnea-impairment was detectable soon enough to usually allow me to pull over to the side of the road to nap now. This was something that pissed off my GF at the time because she'd be expecting me to meet her someplace at time 'X' and I'd not get there until time 'Y' because I'd had to pull off to sleep. And, since this was the mid-90s, the possibility of calling to say "gonna be late: need to nap on the way" just wasn't there.


Apart from the really positive public response (which I'm surprised of, honestly) I got some hate mail / dms. For them I'll leave this here:

"Consider this example: In 2009, a neuroscientist showed photos of people to a dead fish and measured the fish’s brain activity. Interestingly, the fish responded accurately to the emotions of people in the pictures.

This experiment was, of course, a gag. The scientist’s real aim was to show how easily research findings can come about by chance.

Neuroscientists perform brain scans by dividing the scans into thousands of small pieces called voxels, which correspond to regions in the brain. When a brain is scanned (even a dead fish’s brain), there's always some random “noise” in each voxel. As there are thousands of voxels, the odds of one producing data that corresponds to the stimulus given are actually quite high."

The study can be found here: blogs.scientificamerican.com/scicu...


I think you have a point. I would like to train my body to require less sleep. Not by much, I only want to get it down to about 7 hours, as I normally need 8 - 10. I knew someone who needed over 10 hours of sleep otherwise he couldn't function, and I can only assume that isn't healthy.


One of the best pieces of training is pushing things to the extreme for multiple days by keeping yourself super busy, traveling, making a roundtrip around China (that's what I did among some other things), scheduling important meetings for 2 AM or 4 AM and I can bet you will be wide awake later.

Also exercise exercise exercise and try to stay away from smoggy cities + drink a lot (3-4 liters a day works for me, might be different for you). Oxygen intake is really important and water makes up a lot of your body. You need to fill it up with it.


Actually aside from the small number of vegetables you eat, that's actually not an "unhealthy" diet, you're body has learned how to healthily burn the fat and proteins that are in the meat. You don't need as much sleep because you're body can get more energy out of fats and proteins than from sugar and caffeine. So that being said the amount of sleep you can handle makes sense based on that fact alone. I don't know your exercise habits so I can't tell how much is burned from that or how it affects your sleep.


Thank you for the comment. Yes, since I know myself I craved meat but nothing else much, I guess my body just adjusted to that.
My body build is slim and I usually run 10km or swim an hour or do an hour of squash with someone each day, but I wouldn't call this heavy workout. Just keeping healthy.


People, don't rely on vague scientific facts. Experiment with your own body.

This. Averages are just averages, and what might be good for most people is not necessarily good for a particular human being.

I had a similar experimentation process with my diet, trying to figure out when, how often, and what to eat so that it helps me to be healthy. I ended up with a bunch of unconventional habits that work better in my case than the average advice.

Magic number of sleep hours is BS. Try not to disrupt your natural circadian rhythms, sleep when you tired, wake up when you're rested. Boom.


You really received hate mails because of this article? People are so lunatic.

For me, about 6-6.5 hours work. No naps and I try to add a couple of runs/walks every week.

When my second child was born and I stayed home for a month, I gained some experience with multi-phasic sleeping. I slept from around 9 pm to 11pm-12am and from 2-3 am to around 6-7 am.

I really liked that between the 2 phases I was very fresh, but I found it difficult to sleep again. Maybe if I went back to the second phase later it could have been interesting, but the bigger kid wouldn't let me sleep longer in the morning. So I went back to the monophase nights.


I follow this really complex method for sleeping. I start by going to sleep when I’m tired, and then I wake up in the morning (usually 4:30-5:00) 🤷🏼‍♂️


I sometimes feel tired at 2PM. Would you go to sleep then or only after 6-7PM? Do you nap?


I go to sleep about 9-10pm on average.

No naps. Instead I’ll do some activity (i.e push-ups, walk the dog etc...).

I did try doing naps but never woke up refreshed. Whereas a little physical exertion gives you (me) a little buzz. Also I don’t really get tired during the day now that I’ve ditched the naps.

Besides...Naps are for babies, when you grow up you have to GET AFTER IT!! 😈

I count as a baby then. I'm a fan of napping a little and always get up refreshed. I usually don't fall asleep just lay in complete darkness, closed eyes and just turn off for 30 minutes.


7-8hrs is optimal for me! I can pretty much wake up like clockwork exactly 7-8 hours after I went to bed without an alarm because I'm DOA the moment my head hits the pillow and I sleep very restfully. If I wake up in that window and decide to be lazy and snooze longer, I just feel groggy and headachy and worse than if I'd just gotten up when I was refreshed.
If I have to get up with less than 7 hours' sleep, I can function, but definitely not optimally.


But I just want a silver bullet solution :'(


Nice article and I really like the introduction to it.
I like the way the whole article is inspiring the reader to its own experiments. Well done.


Thanks for the kind words! Unfortunately, I got a lot of hate through private channels. My articles seem to be very controversial. Someone either hates or loves them. I really love the people who take an effort to comment on it and share their thoughts. My article is one half, but people sharing their experiences and inspiring each others in the comments is the other half.


I would be happy to hear people who have a system for testing such things or people who disagree with the points I've made and can give a logical explanation so I can adjust my methods 🙏