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Sleep Hacking: 1 Million People Prove Sleeping 5 Hours is Healthier Than Sleeping 8 Hours

Sleep Hacking: 1 Million People Prove Sleeping 5 Hours is Healther Than Sleeping 8 Hours
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Have you been stressing about getting more sleep? It turns out that, statistically speaking, if you sleep 5 hours each night, you’re better off than if you’d have slept 8.   According to the study, 6.5 hours is the sweet spot for lowering your risk of cancer.  In an amazing study published at, a UCSD professor of psychiatry specializing in sleep research and aging has determined that there is no statistical health-related reason to sleep longer than 6.5 hours per night.

It’s hard to argue with him.  He is using sleep data from the Cancer Prevention Study II (CPSII) of the American Cancer Society.  In fact, that data shows that sleeping 5 hours per night (as I’ve done for the last 18 months) is slightly *safer* than sleeping 8 hours per night, at least if you define safe as “not dying.”  Check out the charts:



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  • Lexi

    When I first came across this blog, I couldn’t actually think of what I would do with more time if I had it . . . and now, I’m looking forward to hacking my sleep so I have more time to do all the things I’m excited about! (and not feel overwhelmed about it!)

  • Dave Asprey

    Thanks Lexi! Comments like that make me motivated to keep writing. When you can shed the “I am too tired to do that” excuse, you can – and will – try all sorts of things you’d never have considered. Like climbing very tall mountains, getting advanced degrees, learning languages, or doing something really hard like figuring out how to train cats.

  • Chris Yeh

    What approach are you taking to getting by with less sleep? Polyphasic? Enquiring minds want to know.

    • Adam Barr

      Those of us who are employed in the oil fields are used to minute sleep. Countless 24 – 48 hour shifts. I have been doing it for years. And just when i get a management job, I have a kid. hahaha. I average 5 hours a sleep the past 2 years.

  • Dave Asprey

    I tried polyphasic sleep a long time ago – I don’t think it’s sustainable hormonally or socially unless you’re a hermit. The sleep hacking series here has some tricks, and more coming. But the number one thing you can do to sleep less is to have more energy. You might ask, “I thought you slept more to have more energy…what?” <o:p></o:p> The truth is that if your mitochondria is working at optimal capacity – which happens from nutrition (high healthy fat,  especially MCT, and cutting carbs etc.) – and your sympathetic and parasympathetic systems are in sync (which happens from meditation or from using some cool tech I’m about to post on the site…) you just need less sleep. I also optimize my REM and delta stages of sleep by using a variety of entrainment technologies. This helps, but is not necessary.<o:p></o:p> In fact, a VC friend who went on a higher fat grass-fed butter and MCT oil diet just commented, “I didn’t notice a huge boost in energy because I already feel really energetic. The biggest thing I noticed is that I need about an hour less sleep.” And he hadn’t even done any work on his nervous system optimization.<o:p></o:p> My final sleep hacking post, which includes mostly electronics, is nearly ready to go. <o:p></o:p>

  • Ben Zealley

    Does it not seem more likely that healthier people need less sleep, rather than that less sleep makes you healthier? That seems by far the more likely of the two possible causations implied by this admittedly very well-demonstrated correlation.

    • Dirk

      This was the first thing I thought when I read this.

  • Dave Asprey

    @Ben – Most people think that more sleep makes you healthier. It certainly does make you recover more quickly, but the important idea here is that more efficient sleep can do the same thing. It’s also very much true that healthy people need less sleep, which is why, as I’ve hacked my health, I’ve been able to get less sleep. On top of that, there are the tricks – environmental, chemical, biological, and electrical – outlined in my sleep hacking posts that can safely reduce the already shrinking amount of sleep you need as you get healthier. That said, I haven’t found a way (yet) to be able to do a heavy workout, then thrive on less than 5 hours of sleep consistently. Staying focused, healthy, lean and muscular on 5 hours is easy. Rapidly gaining muscle mass on 5 hours isn’t so easy without drugs. L<o:p></o:p>

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  • Lars

    No offense, but even the linked PR article states:
    “Although the data indicated the highest mortality rates with long-duration sleep, the study could not explain the causes or reasons for this association.”

    More likely that sleep is affect hazard rates is actually lifestyle etc.

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  • Howard

    I would hesitate to put much faith in observational studies, for the reason mentioned by Mr. Zealley. Observational studies tend to miss confounding variables, and are way too easy to cherry-pick (**cough** Keys & Campbell **cough**). Correlation does NOT equal causation.

    I have needed different amounts of sleep at different times in my life, and it’s a subject near and dear to me, since I have had severe obstructive sleep apnea since a couple of decades before the mainstream ‘medical’ community ‘discovered’ it and gave it a name.

    Different people need different amounts of sleep. I would be very interested in knowing why — but not particularly interested in reading speculations on the subject. I’m also very curious about the long-term effects of modafinil (I have used the non-prescription adrafinil at low dosage with very good effect, but it seems to raise blood pressure).

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  • Roger Elliott

    I reckon there’s only one way to determine how much sleep you personally need, which is to allow yourself to wake up without an alarm clock – your brain will take care of the rest.

    • Kaitlin

      I totally agree with this…our bodies tell us what we need. People get so fixated on reading what other people have discovered about average bodies or scientific studies, and I’m sure it’s good to have that knowledge, but wouldn’t the healthiest thing be to know what science says and then apply that to what your own body tells you? There are always anomalies, who’s to say any one of us isn’t one?

      • ClearSleep

        There are many studies that show you can shorten your need for sleep by gradually waking up earlier. It takes at least a week to get used to your new schedule. It’s the quality that determines how long you need to sleep. By improving how deep you can sleep, you CAN shorten the needed hours of sleep per night. I used to need at least 8 hours sleep until I started using an oral sleep appliance that improved my breathing and can now function with only 4.5 to 5 hours of sleep. The prerequisite is a relatively good health though.

      • Harry C. Houdini

        I’m not sure your logic is completely sound there Kaitlin. You say that “our bodies tell us what we need”, but that isn’t always true. For instance, many people’s bodies tell them to keep eating even though they’ve already consumed thousands of calories or hundreds of grams of sugar in one sitting. Or for example, an alcoholic’s body repeatedly tells the alcoholic that they need more alcohol. Just because the human body tends towards certain patterns or behaviors doesn’t mean that the human body is always able to tell us what we need or what is best for our health. It takes rational thought to overcome some of our natural urges that could end up being be harmful to ourselves.
        Furthermore, I’m a bit confused by the contradictory statements you’ve made in your 2nd and 3rd sentences. You seem to knock on the fact that people are fixated on scientific studies, but in the same very sentence, you then act as if people should be know more about science and apply it to themselves. How do you know that those who are fixated on the scientific studies AREN’T applying that to what their own bodies tell them?

        • Spiral

          Its the sub-concious that makes you keep eating when your body is telling you your full but most people ignore that. you just listen to your sub-concious over your body. for example if its something really nice you like and you don’t want to waste it your brain will say KEEP EATING! mean while the body is stuffed he he.

          Just my opinion.

        • Rich Cook

          Folks, guess what? The brain is part of the body! You can’t just separate them out like that.

        • Phoenix

          So true. Our bodies and beings tell us many screwed up things.

        • Sunshine

          I would have to disagree with the alcohol statement, Harry. To the alcoholic, the brain does not tell the body to consume more alcohol, instead, the neurochemical GABA, nature’s chill pill, signals pleasure centers in the brain; thus, the person’s choice to drink more under the misconception of short-term pleasure. If a person never consumes a drop of alcohol, their brain would most certainly not signal the brain to consume this substance. How can the brain crave alcohol when this in not a naturally occurring substance in the body? The choice to drink more is exactly that, a choice; just as in those who continue to eat beyond what the body needs, unless they are suffering from hypothyroidism or some other form of neurological/bodily disease. Additionally, I also believe that when we are healthy, balanced, and true to ourselves, the body will most certainly tell us what we need. This leads me to agree with your statement of rational thoughts to overcome the urges that are not so healthy.

        • Howard Lee Harkness

          Actually, alcohol *is* a naturally occurring substance in the human body. It is an intermediate step in the processing of certain carbohydrates, and a person who is not in ketosis will normally have a BAC of about 1/20th of the BAC that is considered to be the intoxication point for driving in most states. This is the reason the body has the proper enzymes to metabolize ethanol (although you can easily overwhelm the body’s ability to cope with ethanol by ingesting large amounts).

      • Phoenix

        When I only sleep 2 1/2 hrs. per night (which is the way it’s always been for me before meds) I can’t concentrate very well at all. Results in lower grades and inability to function in general.

    • cat

      ive done that and i can sleep for 12-14 hours straight . it doesnt mean i need that long to sleep every single day for me to be healthy or to be able to function normally! just i thought?!? what do you guys think about long hours of sleep?

      • sandra

        It is unhealthy to sleep 10 hours of sleep. I’d say for you, use an alarm clock. That is sleeping your life away. I only sleep 5-6 hours a night. No alarm clock. When I was recovering from major surgery, I slept 9 hours a night.

        • kris

          man, i remember those days after a serious brain injury. not being able to fight the drowsiness that hit me by 10pm sleeping a solid 10 hours waking up completely rested. now i only sleep 6-7 hours avg feeling tired still. never can sleep in

        • Fox

          Einstein slept 10 hours a night. Not saying he was healthy, but the, “sleeping your life away” is bull. Just make more of the time you’re awake.

        • Doodle

          Einstein didn’t sleep 10 hours at once. He slept for minutes at a time when he felt tired. Don’t know where you heard this but he rarely slept a long stretch ever.

        • tyo

          Einstein liked amphetamines.

      • fars

        The brine solve mental and physical problems while we sleep so when ur are sad you mostly tend 2sleep more and also when u are sick , so its realy depend .take care

        • Adam Knapp

          I think I speak for all of us when I say…

        • Rich Cook

          Very funny! :-) Anyhow, in case you are serious, allow me to translate that to good English: “The brain solves mental and physical problems while we sleep. So when you are sad, you mostly tend to sleep more, and the same is true when you are sick. So it really depends.”

    • EBudoy

      but how about me. I only sleep 2 hours a day and It’s very confusing.

      • alexandru benza

        this is the funniest comment i’ve read in a long time. applause, sir.

    • Joe

      Sometimes I don’t feel good after sleeping in long periods of time though. There is such thing as being lazy and refusing to get up. Maybe right when you awaken, not really when you get up and out of bed.

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  • Hattom

    Hi! You got those results you said you’d post, already?

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  • Kathy
    • Kathy

      Hi Dave. How much sleep do children need? I have an 11 yr old. Thanks!

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  • DrewBuddy

    Ugghhh… Correlation does not prove causation.

    • Guest

      No, but sitting on your thumbs and refusing to look at any collected information is far more useless than testing it out and seeing if it works for you.

      • Howard Lee Harkness

        If you have a correlation without a demonstrated cause, you don’t have a study. At best, you have a grant application.

    • Jason

      Where is the causation to prove 8 hours? We just came up with that number out of thin air, jerk

  • Guest

    @”there is no statistical health-related reason to sleep longer than 6.5 hours per night” really? the study suggests 7h/night is the “safest” sleep period, so there is a reason to sleep more than 6h/night; also, your statement may mislead that there’s no difference between 6.5, 6, or 3h/night, which of course is false; note: i do not argue against your ability to sleep 5h/night and be perfectly healthy; we are construing a study here

    • Guest

      why did i feel to post the message above? i really try to find more about a healthy life style but I am really confused when I discover what-seems-to-be-well-scientifically-backed-up-site like yours that looks to conflict in some regards with other sites that I read (scientifically-backed-up-sites, too). But when you say “And if you slept 6.5 hours, you lowered your risk the most” and just below you insert a graphic that clearly shows that 7h/night is the safest sleep time…

  • Emilie Felix

    My whole life I wondered why I felt the best sleeping only five hours! Thank you for this confirmation! I used to try to change my own rhythms and never could. No matter what time I went to bed, early or late, I woke up rested after five hours…naturally!

  • Patricia Ann Taylor

    I have never slept more then 6 hours a night for at least the past 7 yrs if not more, and I function on a daily bases with no problems. So, glad I came across this site.

    • Phoenix

      I would love to sleep 6 hrs. on my own. Even 5 would be great. I only do 2 1/2. Not great.

      • Maurya

        Phoenix, how much time are you spending in bed?

  • Aleonix

    Defining safer as ‘not dying’ and this study was done with participants from a population of cancer sufferers. I’ll guess at different stages of progression and suffering from different forms of cancer, and probably going through different types of treatment… Yep, looks legit!

    • Frank

      Indeed, the least a study like this can do is pick people the same age

    • Eric

      Excellent point, has anyone else considered this. I don’t have cancer and like MOST americans, not in perfect health. Not bad, but not “body hacking perfect” either.

    • Jason

      Actually Aleonix, this study was NOT done on cancer sufferers. It was done on normal people. Read the actual study.

  • ed

    does less than 6 hours sleep significantly decrease testosterone?

  • Erik

    10 hours a day for me of sleep

    • Janine

      I know that feel. If I sleep less than nine hours a night, I get migraines, heavy eyelids, pain in my eyes, a fuzzy feeling in my head, and a slow cognitive tempo. And I can’t focus on anything. Nine is the minimum, ten or eleven is ideal.

      I hate this. I feel like I’m wasting so many extra hours of my life, when everyone else is chipper with seven hours of sleep. I have a nonexistent circadian rhythm as well. I wish I could get an operation to make it so I never had to sleep. There’s always so much to do, so much more I want to read, but I’m too sleepy to stay up. I have great vivid dreams which are somewhat worthwhile, but not really, they’re not worth the wasted hours of my life that it takes to get them.

  • Lawrence of Arabia

    Greetings Mr Asprey and fellow posters,

    Would 6.5 hours sleep provide adequate recovery time for muscle hypertrophy (bodybuilding)?

  • Yuki Tsmui

    wow i’m surprised with this, i thought sleeping less is not healthy, people who sleeps more are healthy, i guess the other sites i checked was wrong. i sleep 5 hours a night, what i was thinking i wasn’t healthy or helping my body to get enough rest. well this information really did help but i think i should sleep about 6 hours, i do get tired sometimes when i’m studying at college. can someone pls tell me if you have sleeping problems can it cause sleep disorder?

  • Yuki Tsmui

    i sleep 5 hours which sometimes i feel great but sometimes i feel very tired, even when i’m at college or helping my family with stuff, sleeping 5 hours is it enough? or not, but I think sleeping more is good for you even if you disagree with me, i mean sleep is food for the brain. during sleep, important body functions and brain activity occur. skipping sleep can be harmful even- deadly, particularly. even sleeping less and feeling very tired can look bad, you may feel moody, and you perform poorly. sleepiness can make it hard to get along with your friends and family.

    another thing many people who sleeps less and get tired can fall asleep while driving cars and others which causes accident and injury.
    i’m just being honest here, but it depends what can of a person you are, everybody is different here some people can sleep less and get enough energy or some people who sleeps more get more energy and feels great. i don’t know i find myself sleeping 5 hours a night is not enough for me, so i should at least sleep 6/7 hours so i get enough sleep and concentrate in college.


  • Richard Brown

    if your only sleeping 2.5-3 hours a night, its because its summer and night doenst drag on forever. you have to have a certain concious (future nostalgia inducing) outlook on the beginning of the morning. that “outlook” releases seritonin. if you dont release seritonin, then you wont release melotonin, making the production of dmt impossable n.n at the end of the summer your body will start releasing horomones that force you to slow down a little bit. this can be an emotionally draining time :/ but its all just trying to make you take on winter sleep cycles, when theres not much in the way of predators X) … or food…

  • robrecord

    Split your sleep (no more than 5 hours at a time, plus any naps you need to catch up) will let you stay awake longer and feel more refreshed. be sure to sleep in 90 minute multiples.

    • Joe

      Five hours has never been a multiple of 90 minutes. can some explanation be made here?

      • robrecord

        It would require a lengthly explanation but these two basic suggestions are a starting point. 90 minute rule is just a basic guideline & does change if you split your sleep up into segments. Beyond 5h of sleep in a single block, there is little additional benefit. More info:

        • Shane

          Actually your body moves from deep sleep 20 mins in and then after that every 2 hours. So 20 min nap or 2 hours. You come into light sleep around every 2 hours and feel way more refreshed than waking up in 90 mins when your body is still in deep sleep. DO YOUR HOMEWORK ROBRECORD.

      • Neill Collins

        15 minutes to fall asleep, 4.5 hours to sleep (3 sleep cycles) and then 15 minutes to wake up = 5 hours. Besides he said no MORE than 5 hours, not 5 hours exactly.

        I kind of agree with this, the best sleep for me is 5 hours at night and a 90 minute snooze in the afternoon. feel good all day.

  • Luluwongs

    First thing I want to know about this research is what is the definition of “sleep”. If “sleep” means the period of time from the moment you just go to the bed until the time you get up, it doesn’t show exactly how long we need to sleep. I usually lay down on my bed but still stay awake for an hour before I become deeply asleep. It also may takes longer than me for other to go to the deep sleeping state, especially those who have the sleeping problem.

  • Ryan

    I’m tired of seeing these bullshit articles on sleep. If your body needs 8 hours a night, then it’s healthier to get 8 hours. If it needs 5 hours, then it’s healthier to get 5. There is no amount of sleep people need to get.

    • Phoenix

      Sooooo wrong. There was a teenage gal on TV about 8 yrs. ago who slept about 22 hrs. a night, every night. I only sleep about 2 1/2 hrs. a night without meds. NOT GOOD. It screwed up my hormones, stress level soared, little ability to concentrate.

  • Antonis Konstantinides

    I do not think i will agree with this article, make this test to people with illness and if you proof that cure will occur faster in patients that will be sleeping 5 hours than those with sleep of 8, then i will admit…i am not a doctor but that sleeping 5 hours doesn’t seem ok to me….

  • JerryShovan

    I don’t think this is true if you are sleeping on mattress like the ones they have over at

  • Marco

    I’ve tried to reduce the amount of sleep several times, but whenever I got under the 8 hours per night the next day I feel bad, dizzy and sleepy.

    • Chris1.rp

      I had the same problem now I sleep just about 6 and I don’t use alarm just before you go to sleep think in sleeping 6 hours and what time will be when you should wake up, and other change i had is that now I excersice every 2 days very hard, before was 0 excersice.

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  • Joe

    This is BS. Someone undergoing cancer treatment and is about to die would not be able to stay awake very long every day and thus get more hours of sleep. Obviously those who are in so much pain that they cannot sleep will also die relatively soon. This sample of people does not accurately depict the healthy amount of sleep for a healthy person.

    • Jason

      This study wasn’t done on cancer patients Joe.

    • Klunge1234

      Fuckin idiot

  • me

    wouldn’t we say that because more people sleep actually sleep 7 hours a night, therefore there are more people in the ‘hazard ratio’?

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  • RKR

    I didnt sleep for a week during exam days… and I slept only for 3 hours a day some 15 years back… 3 years back im diagnosed having MVP and need minimum 7 hours of sleep,… How do u people explain this?

    • Jozep

      Heck! I’m just finding out about ‘all this’ and am still struggling with ‘eating butter to lose weight’! But, I’m drinking my first BP coffee right now! So try to be more open…cause I’ve NEVER been able to sleep just “3 hours a day” while you’re living proof that some can…

  • Jason

    I am not sure why people think this study was done on cancer patients….. This was done on normal healthy people. Read the damn study PEOPLE !

    Briefly, data were examined from more than 1.1 million participants, mainly
    friends and relatives of American Cancer Society volunteers, who were a
    diverse selection of American adults ranging from 30 to 102 years of age.

  • No-brainer

    This is stupid. Everyone is different. At best this info can be considered an average, but I hope people aren’t changing their sleep habits because of posts like this. We naturally sleep in mental healing cycles (around 3 hours-ISH), don’t interrupt one of these and you’re fine. You can usually feel when one ends because you drift closer to awake and sleep lighter. The more of these healing cycles you get, the more stable your ever-changing cognition is. Not enough: mentally unstable. Too many? I guess it could maybe make accepting change a little tougher! And yes, if you stress out more, you age faster. Duh.

    • Klunge1234

      Your missing the point aha, dont think you have read everything dave has said. HEALTHY PEOPLE NEED LESS SLEEP

  • chelseyam

    I’d have to agree that sleeping
    excessively can be unhealthy. Typically if I sleep more than I need I
    seem to be groggy all day and just want to go back to bed. My problem
    with people who want to sleep less is the entire idea of exhaustion.
    A lot of people who seem to push their bodies with less sleep often
    do so to work
    The more work they do the greater the chance of having a breakdown. I
    think with many people the 8 hours might be needed just to get them
    to slow down a bit.

  • Nadia PB

    I attended a lecture consultant specialising in sleep, and if I recall correctly, there is a genetic component involved in how much sleep an individual needs – ranging from 4 to 10 hours. This study, I presume, were made based on subjects used their existing sleep patterns. My concerns are that perhaps the physiological benefits may vary greatly between individuals when it comes to sleep reduction, depending on what their individual genetic predispositions are for sleep quantity. Therefore can we really say 5 hours sleep is a good idea for everyone? I don’t think we could know unless we trial it (I’m sure there should be existing trials of sleep reduction experiments – if anybody could direct me to them I’d really appreciate that). Any thoughts from the author/anyone else regarding this?


    actually if those healthy people would sleep 7 hours they would live even longer ,the same visa versa less healthy ones would sleep just 5 hours they would go much faster ;


    healthy people need less sleep ??
    well; healthy people needs healthy support ,if lets say you had a fasting day ,you need more sleep ,same if one had a tough day he may need more sleep ,
    kids sleep more deep sleep ,adults may take it in more hours of sleep ,

    • Howard Harkness

      That has not been my experience. On the day following a fasting day, I generally wake up earlier. Sometimes an hour or more earlier than usual. Without any unusual daytime drowsiness.


        how is your fasting day ,its been without anything taken in your mouth for one full day ?
        how is your activity at that time being ?

        • Howard Harkness

          I don’t usually do a complete (water-only) fast. I will do a partial (600-700 calorie, mostly fat) fast. I do not change activity level when fasting, but most of my daily activity these days is loading boxes onto my truck to take them down to the shipping place (and unloading them). I don’t have to handle anything over about 45 lbs (UPS limit is 50).

  • Howard Harkness

    “statistically speaking”

    That’s level 3 on the ANSI standard mendacity scale. 1)Lies, 2)damned lies, 3)statistics, and 4)government promises.

    Observational studies do not establish causality. Period. At best, they provide a question to be asked of a controlled study. At worst, they provide fodder for egregious headlines by ignorant reporters.

    Unfortunately, it would be difficult to make this into a double-blind, so you would have to contend with two of the most powerful forces in the modern pharmacopia — the Placebo Effect, and its evil twin, the Nocebo Effect.


    Not sure what all this fuss is about, I just regularly consume Adderall or Cocaine and I’ve got no issues staying awake..2-3 Hours a night is plenty.

  • Joel Brothers

    The study you quote was done in 1982-1988, and has since been disproved, especially by the most recent study by the University of Pennsylvania Hospital (
    8 hours of sleep is the the average threshold below which motor skills begin to deteriorate.

  • Brooke Nickerson

    I have been trying to sleep only 6.5 hours since I’ve read this article instead of 7.5-8, hoping it would work for me. I’ve woken up feeling awful and have not been able to get out of bed until after 7.5 hours. This morning has been the worst yet, and I’m going to stop trying. I think people should just listen to their bodies and learn when they should not as well.

  • Dwong

    Although there are many benefits to sleeping more, notice there are many people out there who don’t sleep or sleep around 1 or 2 hours per night. This schedule really helps people who truly have a lot to get done. I personally follow this schedule with no side effects (I pride myself in my excellent reaction time after a couple all nighters haha). That being said, it always feels nice to sleep in when you don’t have much to do the next day. Moral of the story: sleep is good, sleep the optimal amount for your health.

  • anonymous

    It is possible to get by on four hours of sleep if you live a sedentary lifestyle, but I run and weight train. I need 8+ hours of sleep.

  • Markus Rosnes

    i usually sleep for about 8-9 hours everynight, but recently iv been waking up after 5 hours of sleep, no alarm clock, just i wake up after 5 hours, feel refreshed, check the clock and im usually like “WTF IV ONLY SLEPT 5 HOURS I NEED TO GET BACK TO SLEEP” but truth is i feel bether than ever, idk why i just suddenly changed my sleep rhythm, it just happened naturally.

    i did have a period in my life where i slept 2 hours and woke up for school, then when i came home i slept for about 6 hours, it was bad.

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  • Stan

    “prove” is somewhat optimistic. A single observational study is of limited value. We’ll just gloss over the lack of causality and self reporting questionnaires have accuracy issues. The follow up check for deadness was only 6 years out. The age range was like 30-102 all the folks at the low end could have subbed meth for sleep and probably not died.

  • Siggster

    What I personally noticed, and from personal experiences. Happier people tend to not need to knock-out for 8 hours and up. When I was going through emotional issues, depression. I was able to sleep 10-12 hours and be FINE. When I was healthy and happy, I can tell you that I slept for 5-6 hours at the most and was completely fine. For someone who has goals in life, i think 8 hours of sleep is a waste of time. Also, the happiest people i know are capable of sleeping only 5-6 hours as well. My view on it is, the sadder and less driven you are, OR the sicker, the more you don’t wanna be up. Thus causing you to sleep 8 hours and even longer.

  • YoMama SueEllen

    I’m not a scientist (yet) but for some reason I don’t think this makes much sense. I love to sleep, I LIIIVVVEE to sleep. I think there’s a hidden factor here, just because there’s a correlation, doesn’t mean that one causes the other.

  • Patrick

    Lifehacker point to a study conducted which paints a pretty clear picture of how much sleep is a good amount of sleep. Having said that, other studies suggest the amount of sleep entirely depends on the person.

  • Patrick

    In the study – four and six hour groups were found to be impaired to the point of being “the cognitive equivalent of being legally drunk”

  • John Gilas


  • John Gilas

    Right all you fellow insomniacs While your reading this I’m going to bed
    (For my 5 to 5.5 hours!) unless you’re already asleep ofcourse

  • Nsima Inyang

    I’m very curious if there would be a difference in athletes that have heavy intense workouts(bodybuilding, runners, etc). A cool test would be to have this study done on athletes to see how their muscles would repair at night and if it would be more effective to get 5 hours or 8 hours. To be honest, i feel very groggy when i get 8 hrs of sleep, and feel the best at 5-6 hours, but i’m curious if it would have an effect on how my body recovers…meh time to search the net.

  • Greg Gregerson

    Now let’s get some research on the main issue: How the hell do you wake up?!?

  • Elle

    I’m 26 years old and I’ve spent a large portion of my life sucking at sleeping. Here’s what I know…. Quality, people. The quality of your sleep is what is important. Sleeping 8 hours of restlessness will not help your body recover from the day the way it should like 6 hours of REM. A few tricks I’ve learned are: 1) Create a routine. Wash your face, brush your teeth at the same time every night. 2) Lay on your bed, close your eyes, and for 5 minutes think about all the things you are grateful for. Might sound crazy but I promise that putting good thoughts into your mind before you sleep will only help your overall health. Lastly, 3) and is my favorite… I streamline thoughts. Often before I go to sleep my brain swims with all kinds of thoughts. Good, bad and ugly. So I do what I like to call a brain dump before I go to sleep. I take a piece of paper and write down every single thought or word that pops into my brain. I do this for 5 minutes and then when I’m done, my brain is empty and I am finally ready to sleep.

    It’s helped me go from tossing and turning for hours at night to few and far between wake ups. My energy level is better and my overall wellness is better. Hope this helps my fellow sleep suckers!

    • Stef

      This is exactly what I do, as a kid it sometimes took me 2-4 hours to fall asleep because my mind was constantly thinking about stuff/discussions that happened that day. Having a routine helps a lot. Another tip I would add is ventilate your room well, fresh cold air makes me sleepier while I’m comfy under my blankets.

      When you’re restless because of random thoughts trying to dream helps too, don’t think about worrying thoughts but dream about the stuff you are thankful for or stuff you would like to do (or already did) with your loved ones.

      If you’re running on a tight schedule don’t look at how much hours of sleep you’ll get or have left that night, that will make it harder to go to sleep too. I set my alarm the morning before so I don’t have to worry about that when I go to sleep. When I’m on a regular schedule, my body will wake up naturally before my alarm though. Even if it’s only after 4 hours.

  • Max Utter

    Most of your posts are spot on, but in the case of referencing the UCSD sleep study you did not use the deep investigation your known for. The UCSD study was done by the cancer research group, and the subjects were largely cancer victims. Cancer patients tend to fatigue quickly and the more advanced stages they reach the more time they spend sleeping. This study has been refuted and debunked as not apply to healthy people and there are many, many studies showing cognitive decline, poor health outcomes, weight gain and other health issues for achieving less than 8 hours of sleep continuously.

    I would be happy to refer you to more recent and appropriate research.

    All the best,


    • Phoenix

      You seem very up on this subject. I only sleep 2 1/2 hrs. a night (without meds) all my life. definitely not a good thing for the body nor the brain.

  • Rich Cook

    When I look at the charts, it looks like 7 hours is the optimal *statistical* point. Also it pays to remember that statistics are only valid on populations of people, not individuals!

  • quinnn10

    I’m confused…how is eating less calories to lose weight an incorrect theory?? obviously if you eat at your caloric maintenance you won’t gain/lose weight and if you eat above it you’ll gain weight. how is eating below it not a way to lose weight? or did I just interpret that wrong?? I’m so confused right now and could use further clarification

    • David

      The high carb low fat diet insists you will lose weight by eating unprocessed fruits and veggies and eating a lot of it. Food deprivation is unsustainable in the long run. If you want to keep it off, you need to eat a lot of nutrient dense carbs.

  • meh

    This is ridiculous. It studies cancer patients, first of all. So if you don’t have cancer, you might wanna reconsider… SECONDLY, there are so many other factors that determine whether you live or die as a cancer patient that I can’t take this seriously right off the bat.

    Also, where’s the source? Cite it, man. I want to have access to this because if I don’t, I have no idea how you’re manipulating the data. I also agree with the comment below mine– what other factors contribute to needing to sleep more? Are the patients incredibly stressed, laying down for 3 hours, and sleeping for four; while healthier patients simply just get to sleep faster and can do alright on 6.5 hours?

    I’m an audio engineer and I’m just grinding through it. I don’t recommend it. 6.5 Sounds luxurious to me, though!

  • Bob

    i want my time back for reading this article

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  • Marwa Zaghdoud

    good news :D !!!but i afraid of falling down someday !!!!

  • Ceylan

    Of course, as usual, there is the mistake of thinking like there is only one correlation. Here, with this data, we show that sleeping less is not correlated with higher risk of cancer etc. etc. OK I respect the findings, however, where is the data showing that lack of sleep doesn’t damage neurons in the long run? Because I am pretty sure it was only a week ago that experiments in mice showed permanent neuronal damage associated with extended sleep deprivation.
    Not only that, but also there is extensive research going on about disrupted circadian rhythms and the correlation to cancer progression. There is some solid data there already, pointing out to a correlation. I can see this article was posted long ago, but I think it should be removed because it can be misleading.

  • traffikoo

    There is more to life than avoiding cancer.

  • Clay

    I agree with this article. Although 6 hours a night is optimal for me, I have made it off of 4 a night for several weeks at a time. It’s amazing how our bodies get used to it. I have also slept 8 hours a night for a couple of nights but I can’t seem to do it every night because my body only needs 5 to 6.

  • MJ

    Is this without or without a nap? Because if with a nap. Then it’s not supprising

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