Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
12 Jun

How to Conduct a Personal Experiment: Biphasic Sleeping

It’s time for another edition of “How to Conduct a Personal Experiment.” Last week, it was the cold water plunge. Today, we’re going to talk about running a biphasic sleep experiment. First, though, I’d like to know: how are the cold plunges going? Are they, well, cold? More importantly, did you have any difficulties setting up the experiment, identifying variables, and choosing what to measure and track? This whole personal experiment stuff is likely new to most of you, and while there’s no real “wrong” way to go about it, there will be some initial difficulties. Be sure to keep us posted in the comment section.

Okay, on to the new experiment.

Biphasic sleeping is exactly what it sounds like – two-phased sleep. Instead of monophasic sleeping, which is sleeping in one big unbroken block of time, biphasic sleeping is broken up into two chunks of time. I wrote about biphasic sleeping last year, explaining how considerable evidence suggests that biphasic sleeping is actually the natural sleep pattern in humans. Before the Industrial Revolution, back when darkness meant bedtime and keeping the light on after dark required the consumption of expensive candles and lamp oil, people had far more exposure to darkness. They didn’t have iPhones, laptops, big screen TVs, or even lightbulbs. They had the moon, the stars, the campfire, or maybe – if their city had implemented them – street lamps that were really just candles in glass. And this shorter photoperiod resulted in a very different way of sleeping:

You’d get to bed shortly after darkness had fallen and sleep for several hours. This was “first sleep” (later mistranslated as “beauty sleep”). Sometime around midnight, you’d wake up. You’d putter around, read a little by candlelight (if you were literate and could afford candles, that is!), make love, get up and dance, check on the animals, talk with friends or folks in your tribe, think of stately pleasure-domes in a partial waking dream state… that sort of thing. In short, you would be awake and at least moderately active. You’re not a groggy, grumpy person here, fussing with your pillows, thrashing at the comforter, and agonizing over the alarm clock. You’re reasonably alert and cheery.

Then you’d drift off to “second sleep.” Sounds cool, right, but out of the realm of possibility for us living now? Maybe not.

Studies find that modern humans living in an technological permaglow of light will revert back to the biphasic sleep pattern when exposed to shortened photoperiods (from 16 hours of light to 10 hours of light), so the potential remains.

But very few of us are humans living in contrived study settings, and that’s what could make this one a little tricky. Ideally, biphasic sleep is effortless. It just happens. You wake up, read, talk, use the loo, or do something gentle for a few minutes or a couple hours, and go back to sleep without actively trying to make it happen.

That won’t work for everyone, not without active intervention and formal experimentation. Which brings us to the personal experiment.

But why biphasic sleep?

Mostly because I find the notion that we’re all “doing it wrong” when it comes to a fundamental aspect of our lives – sleeping – extremely interesting. I mean, it’s not like it hasn’t happened to us before (diet and exercise, anyone?). It’s not out of the realm of possibility. I’d even say it’s fairly likely that we’re getting something wrong when we sleep, seeing as how 60% of Americans between the ages of 13-64 report having a sleep problem almost every night, whether it’s waking up feeling groggy or waking up too early. Even those of you who are clued in to the whole Primal thing might find it helpful to explore another way to sleep. In my last post on biphasic sleep, I referred to it as more of a thought experiment than anything else, but today I’m recommending people formally attempt to integrate it into their lives, if only for a month or so.

That said, is there more than one type of biphasic sleeping? Sure:

Natural biphasic sleep

This is what I call normal human biphasic sleep – two four-hour blocks of sleep broken up by an hour or two of wakefulness in the middle of the night. Easy to understand, if hard to implement.

Modified biphasic sleep

This is the kind of biphasic sleep that lifehackers employ. They’re not really interested in anthropological or evolutionary arguments for sleeping a particular way; they want to save time and get the minimum dosage of sleep that confers the maximum amount of benefit. They see sleep as a waste of time, albeit a necessary one. From what I can tell, lifehackers typically sleep for a 4.5 hour block of time – say, from 2 AM to 6:30, which allows them to stay up late, get three, full 90-minute sleep cycles in, and rise early to greet the day. They follow up with a 90-minute nap sometime in the late afternoon, which gives them another 90-minute cycle and enough energy to make it to the next sleep block.

Sidenote: I’m somewhat skeptical of these shortcuts when it comes to sleep. From what I can tell, they focus on REM sleep and seem to classify non-REM sleep as “wasted” sleep, as if it exists only to propel us from one REM session to the next. Eh, I’m not so sure we should be so flippant about messing with a vital physiological process, nor should we immediately discount the importance of “useless” sleep. I have no problem with hacks, usually. In fact, I usually welcome them. Just be careful when hacking something like sleep.

Okay, so how do I do it?

First, you want to determine what kind of biphasic sleep pattern is even possible for you. If you have the freedom to get to bed shortly after dark, wake up in the middle of the night for a couple hours, and go back to bed, go for natural biphasic sleep. 

  1. Choose an “absolute latest” morning wakeup time. If you have to be up by 7 AM, that’s going to determine how late you can go to bed.
  2. Determine a bedtime. It should be at least nine hours from bedtime to morning wakeup time, giving you two four hour sleep blocks and one hour of free time in between. If you’re up by 7 AM, you should be in bed by 10 PM. If you want another hour in the middle of the night to do stuff, go to bed by 9 PM.
  3. Reduce exposure to artificial light once the sun goes down, or at least two hours before your scheduled bed time, just like it would have been for most of human history. Turn off the TV, install f.lux on your computer, light some candles, and/or wear blue light-blocking glasses or goggles. It probably won’t work as well otherwise.
  4. If you use lighting during your mid-phase waking period, be sure to wear blue light-blocking goggles or stick to a natural light, like candle or yellow light. Try not to bust out the PS3 for some online gaming.

If you need more alert waking time in a day and would like to try reducing the amount of sleep you require, try modified biphasic sleep.

  1. Choose a 4.5 hour block of time. This will be your “anchor” block of sleep, and most people have success placing this at night or during early morning. Try 10 PM-2:30 AM, perhaps, or 2:00 AM-6:30 AM. Set an alarm, at least until you become entrained to that schedule.
  2. Wake up and go about your day. Get some light exposure, preferably daylight if applicable.
  3. Take a 90 minute nap, to begin 8-10 hours after your wake up time. If you woke up at 6:30 AM, you might nap from 4:30 PM-6 PM.

Set a realistic goal:

  • “I want to improve my sleep.”
  • “I want to feel just as refreshed on less sleep.”

Come up with a hypothesis, like:

  • “Modified biphasic sleep will reduce my sleep requirements while maintaining my wakefulness, productivity, workout recovery, and immune function.”
  • “Natural biphasic sleep will reduce my nighttime anxiety about waking up and ruining my sleep, thereby improving my sleep.”

Now, we identify some of the variables and think about how they might affect the outcome:

  • Length of sleep blocks – Are four hours enough during natural biphasic sleep? Do you prefer two three hour blocks instead of a 4.5 hour block and a 90 minute nap?
  • Timing of sleep blocks – Do you need less time in between the anchor block and the nap? How do you sleep with one hour between your two sleep phases? How about two hours?
  • Alarm – Does the alarm help or hinder your biphasic sleep?
  • Light – How does light exposure affect the effectiveness of your biphasic sleep? Is total abstention before bedtime necessary?
  • Activity while awake – What are you using your free awake time to do? Does reading by candlelight have a different effect on sleep quality when compared to going for a walk?

Next, let’s take some measurements. What to measure?

  • Productivity – Is your work suffering or improving? How many productive hours are you getting?
  • General wakefulness – How are your energy levels throughout the day? Are you getting a mid afternoon slump? Use a simple 1-10 scale.
  • Grogginess – Do you feel well-rested upon waking? After which phase do you feel the most rested? 1-10 scale.
  • Recovery – How are your workouts? Are your numbers improving or falling?
  • Immune system – Are you getting sick more often?

Try the biphasic sleep for at least a week, preferably closer to four weeks. Then once you’ve established a baseline and have some data to work with, refer to the list of variables above, make a change to a single variable, and give it another try for some duration to see if biphasic sleep is for you.

This isn’t for everyone. As Robb Wolf points out, when you have 14 hours of uninterrupted darkness and potential sleep time, you have the luxury of being a little more picky with your sleep patterns. When you don’t have emails to answer or an unprecedented renaissance of quality television to tear into, you’re going to get sleepy when darkness falls, go to bed pretty early, wake up after several hours, do your thing, and go back to sleep for another several hours. Biphasic sleep is probably natural. But we’re not living in very natural times. Or, if we are, natural means something different from what it once did. That’s the whole premise of the Primal Blueprint, after all – identifying what our ancient genes expect from the environment and figuring out how to modify our modern environment to fit those genes.

Let me know what you think in the comment board, and be sure to check out today’s contest.

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Awesome post Mark!

    Years ago I trained for a marathon during the hot summer months and preferred to do my long runs at 4am to beat the heat. My life didn’t allow me to get to bed super early so I started biphasic sleeping. I slept usually from 11 to 3:30 and then took a couple hour nap after work in the late afternoon.

    It was great. I was never tired, even with my demanding running schedule. And I really enjoyed the different schedule.

    I’ve been thinking about taking it up again in my later months of pregnancy (so I’m happy to see this post), both because I often have to pee at 4am and because it would be good preparation for having a little baby around. 😉

    Peggy The Primal Parent wrote on June 12th, 2012
    • This is exactly what I do every summer, nap every day, and I love it! I get up, do a training run, get some chores done, nap, and then get up for the rest of my day. LOVE IT!

      But I’m a teacher and can only get away with it in the summer, unfortunately. There is no “nap time” built into the school day anymore. :-(

      Royanna wrote on June 12th, 2012
      • Omg I miss nap time!

        Gem wrote on June 13th, 2012
    • I never knew you used to be a marathon runner! What made you quit?

      Do you run at all now days?

      Primal Toad wrote on June 12th, 2012
  2. I just said last night that if I want to get everything done I’m going to have cut back on sleep. There is very little else I do that can get elimnated. Maybe this is the answer!

    Ham-Bone wrote on June 12th, 2012
  3. This is very interesting. I’ve been going to sleep at 10 pm, waking at 2 am, reading or puttering around for a couple of hours, then going back to sleep at 4 and getting up at 8 or 9 for a few months now. It just happened naturally and I just thought there was something wrong. I had no idea it was considered a “normal” sleep pattern. You learn something every day. Since I work from home and have the luxury of choosing my own hours, I’m just going to continue doing what my body seems to want to do.

    Joanna wrote on June 12th, 2012
    • Same here. Good time.

      Ma Flintstone wrote on June 12th, 2012
    • So you just randomly began waking in the middle of the night consistently?

      Do you have more energy during this type of sleep?

      I am very interested in trying this experiment out. I can’t start but may do this once I land in Olympia in 2 weeks!

      So, I’d love to learn about more experiences.

      Primal Toad wrote on June 12th, 2012
      • Primal Toad,

        You might find it hard to get to bed early enough without blackout shades in Olympia in the summer as the days are long in the PNW (it is usually still pretty light at 10:00 pm, especially on clear days, and bright again at 5:30 am). Much easier to do in the winter months where there are barely 8 hours of daylight…which is mostly clouds. :) Long days equal more time for fun after work…but bad on your sleep cycle. Haha…

        M Greye wrote on June 15th, 2012
  4. Ok, sounds great except it takes hours for me to simply fall asleep… Ambien made it better but still.

    I sleep about 4/5 hours a day and I can call THAT a good night o’ sleep.

    Nossar wrote on June 12th, 2012
    • I gave up on drugs for going tosleep when I went primal. I have tried them all in trying to deal with sleep issues. I have found Magnesium and Melatonin now do the trick to help me into sleep. Recently I have been using an autohypnosis track to help me ease into sleep- the Iphone allows me to set it for 90 minutes or so, so I don’t listen to an endless loop. This helps expedite going to sleep, and seems to keep me asleep longer.

      SueB wrote on June 12th, 2012
  5. I’m glad you’re sharing these guidelines and suggestions for personal experiments. This one is equally as compelling as last week’s for me for I just realized my poor, SAD, exhausted body did this naturally for a while about 8 years back. Commuting 3 1/2 hours a day to a long and stressful job, mothering my young child, and the various household chores & cooking was a great stress on me back then . I’d find that I’d literally ‘pass out’ (well, fall asleep), after my son’s bedtime for about 3-4 hours. Then I’d naturally wake up and do some household chores for an hour or two, then get back to bed for a few more hours of sleep.

    I’m definitely going to try this experiment now that I’m travelling a calmer, primal road.

    KerryK wrote on June 12th, 2012
  6. I would LOVE to do this – I’m working two jobs over the summer in an attempt to take on as low a student loan amount as possible, and there are never enough hours in the day to get all my work and chores done and also get enough sleep to feel ok. I just moved from the country to the (loud, bright) city and will be installing light- and noise-blocking curtains sometime this week, which should help a bit with getting uninterrupted sleep, but needing fewer hours overall would be amazeballs.

    A question for anyone who feels inclined to answer: my two jobs are as a programmer and a baker, so I’m inside all day (anywhere from 7-15 hours at a time), either under fluorescent kitchen lighting or staring at a screen. I’ve already started scheduling 5-minute breaks to walk around my building when I’m programming, but I can’t do the same at the restaurant. Will this much exposure to this kind of light make it harder for me to try polyphasic sleep? I already use as few lights as possible when I’m at home and am planning to get some oil lamps to use in the evenings, but I spend much less time there, unfortunately.

    Nelly wrote on June 12th, 2012
    • Sounds like awesome experiment controls to me! Let us know how you think it works out.

      Becky wrote on June 12th, 2012
  7. Very interesting article! It’s fascinating to hear how this has worked for other people, and we like the idea of a more “natural” sleep routine.
    And naps are pretty great!

    Alook Training wrote on June 12th, 2012
  8. This is what I naturally do during the winter months. I’m generally asleep (or fighting it) shortly after dark, wake up around midnight, get up and do a few things, go back to bed an hour or 2 later and sleep for another 2-3 hours. I thought it was a problem. Who knew?

    Myra wrote on June 12th, 2012
    • When I lived by myself and could control my environment I tended to get ready for sleep when dusk arrived, wake up in the middle of night for a spell, and then awake with the sun. This is the only way I feel refreshed in the winter. But now with a full house, no deal.

      Paleo Bon Rurgundy wrote on June 12th, 2012
  9. When I was (much) younger I worked in a pub until midnight and started work as a breakfast waitress at 5am. I caught a few hours between jobs and then again a few hours later. It was awesome even though I usually got only 6 hours sleep.

    These days, I often wake at 3-4am, get up and do some work then go back to bed for a few hours or simply stay up and nap later in the day. I *never* feel tired if I do things this way and now regard my early morning wakings as a gift.

    Alison wrote on June 12th, 2012
  10. I’ve been doing this ever since I got a puppy with a “tiny bladder”. He’s now 9 years old and he still needs to go outside to pee in the middle of the night. So sometime between 1:00 and 3:00 in the morning he’ll wake me up (and the other two dogs) and we all have about a 15 minute potty break. I don’t turn the lights on, so it’s easy for us all to fall back asleep when we’re done.

    Nancy wrote on June 12th, 2012
    • Hah — some of us can’t blame the tiny bladder on the dog!

      I did notice that last night I went to sleep around 8pm, woke around 12:30, and again around 5am — that one WAS the dog. We went out and back to sleep and slept until 7:30. Probably 10 1/2 hours sleep total and I feel great this am.

      Diane wrote on June 12th, 2012
  11. I wake many times a night to nurse my toddler. Since he was a baby he sleeps a few hours first, then the rest of the night is much more unsettled with lots of nursing. This seems the norm among friends who co-sleep and breastfeed. The obsession people have with ‘sleeping through the night’ is clearly expecting too much from an infant!

    Olivia wrote on June 12th, 2012
  12. When in central Africa with no artificial light I slept better than ever before. My husband would often wake in the night and chase rats around the hut with a machete! Now I know why.

    Olivia wrote on June 12th, 2012
    • LOL “chasing rats around the hut with a machete”… I think I might need to make this a euphemism for some mid-night activity…

      Tom Bassett-Dilley wrote on June 12th, 2012
  13. This is an interesting post since my sleep patterns follow daylight. In the wintertime, I have no problem going to bed early 7pm reading for a little bit and sleeping for 11 hours or so. In the summer, I can’t go to sleep if it’s still light so it’s usually not until around 10pm then I’m up again at 5am. Since I do best in 9 hour of sleep realm, I usually take an afternoon hour or so on the weekends, in the summer.

    Tammy wrote on June 12th, 2012
  14. I’ve been doing since February. It’s great – try it!

    Jan Madsen wrote on June 12th, 2012
  15. I seem to follow this biphasic sleeping pattern only to be told by my naturalpath doc that this is stressful due to cortisol out of wack and recommends supplements to help me get a better nights sleep to normalize my hormones. I would love to jump put of bed and have a ton of energy. I don’t have any coffee or tea. I am so confused what should I be doing ?

    Jina wrote on June 12th, 2012
  16. I do this almost every night! It’s called having a newborn. 😉 All joking aside, since going full on primal with diet and activity after her birth, I have noticed that despite my sleep being interrupted through the night (for anywhere from half an hour to an hour), I’m not a grumpy groggy mess in the morning. On the contrary, I am up and ready to tackle the day with my 2 year old son and my baby girl. :) I think you may be onto something here, Mark….

    N3P3N7N3 wrote on June 12th, 2012
    • I am the opposite. I’ve four little ones (6yrs – 4months) and I co-sleep, but I am “waking” every two hours (or more)to nurse. Even though I exercise and our family has switched to being Paleo… I am exhausted, cranky, always hungry, and stomach burns.
      I can’t tell if it’s just allergies, my body adjusting to new eating habits,the lack of darkness (live in AK), stress, or the constant nursing wearing me down? Sleeping more and feeling great would be wonderful!
      I’d like to see Mark do a post in regards to nursing mothers and how we can stay fit (getting into all my pre-baby clothes would be awesome too!)stay awake, and over all being Paleo while nursing (and even pregnant).

      Megan wrote on June 12th, 2012
      • 4 month old babies feed a lot, make sure you’re eating enough. And 4 under 6? Enough to wear anyone out!

        Olivia wrote on June 12th, 2012
        • Have to agree with this one. Price’s studies were enough to convince me to space kids at least 3 yrs apart. One great line from his study in a remote pacific island was that husband and wife sleep in separate huts until the newborn reaches two or three years, at which point the child no longer need their mothers exclusive attention, and the mother has recharged her vit.A supplies needed for the health of the next baby. Husband and wife can then get together again.
          The line among the tribe was something like ‘If this protocol isn’t observed then the parents deserve everything they’ll get.’ Hardly fashionable with CW,
          nor help to Megan- sorry! But keep it in mind breeders…

          Ma Flintstone wrote on June 12th, 2012
      • you are a perfect candidate for Dr Kruse ‘s cold thermogenesis protocol. The cold triggers leptin to replace the normal light/dark signals. Living in AK gives you access to cold water sea food and plenty of cold water/air to convert WAT to BAT. One big caution is not to kill too many fat cells as they will release their stored toxins when they die, not great for breast milk.Your sleep will improve dramatically and so will your kidd’s

        Greg wrote on June 12th, 2012
      • Sorry to hear that you are having some troubles, Megan! :( My daughter was born with Pierre Robin Sequence and a Cleft Palate. Due to her inability to get any suction, she was unable to nurse and we have to feed her with special bottles. Even with pumping, I was unable to keep my milk in, so we were forced to supplement with soy formula. My milk never came in fully for my son, either, so I’m not sure why I’m broken in that regard? :(
        Anyway, this obviously means that I am not up ever 2 hours to nurse, more like every 3 to 4, but I am always on ‘mental alert’ listening for her breathing or if she swallows her tongue/chokes on spit up due to her condition. If I sleep too well, I sometimes wake up in a panic to check on her. We don’t co-sleep, but she is in her crib less than 2 feet away from me.
        Anyway, I’m not sure why it works for me, but I consider myself incredibly lucky that I have the energy to deal with my toddler, my baby girl, and keep the house without having a meltdown. I hope that you are able to figure out what works best for your body soon! Sounds like there is a bit of tweaking that may need to be done?
        Take care!

        N3P3N7N3 wrote on June 12th, 2012
        • N3P3N7N3, it made me so sad to see your comment about being “broken.” I have had several friends with supply issues and I can barely imagine how awful and frustrating that must feel (my first LO is almost five months old, so I totally get the overwhelming new-mom guilt, regardless of its source). But you are NOT broken! Many, many women struggle with low milk supply due to a huge variety of causes, both genetic and cultural. In most hunter-gatherer societies women typically co-nurse the babies of close friends and relatives, so a single mom with a low milk supply would still successfully raise a healthy baby. That’s part of why the problem is so common, since the genetics that may contribute to it are still with us today. Unfortunately there are a lot of institutional structures that compound the problem and since we no longer co-nurse, many mothers have no choice but to use formula. But you are NOT BROKEN! You are the best possible mom to your LO and she is so lucky to have you!

          Basbleu wrote on June 19th, 2012
        • As Basbleu said, the issue of not being able to supply enough milk is anything but rare and does not make you “broken”. My wife fought hard to breastfeed our son but it was clear he wasn’t getting anything and was going hungry. It was frustrating her, making her sad, and worrying us — and leaving him hungry.

          Tons of mothers have problems breast-feeding. It’s so very common you really shouldn’t be worried about it at all. When we finally realized it, and stopped thinking it was “Gods Plan” that our son be breast-fed, the guilt associated with it went away. We embraced formula, and are now so grateful that God/nature created some really smart people to create a pretty decent product called formula in order to help us.

          Our son has only ever been formula-fed. Yet he’s slightly taller than average, strong, active, healthy, and smart as a whip (he’s now 2-1/2). I’d say the formula works pretty well. Of course, breastfeeding is better if you can; but if you can’t, formula is amazing and you shouldn’t be ashamed or feel “broken”.

          The fact your baby has such a caring mom is proof you aren’t broken.

          Brandon wrote on June 19th, 2012
      • Hi Megan,

        I think it makes a difference whether you wake up by yourself (naturally) or because your little one wants mommy/nursing time. The two of you are of course attuned to each other, but when you’re awakened in the middle of deep sleep, 3-4-5 times a night, that can really make you foggy. I remember feeling overall tired, but not specifically in the mornings. Usually I still hit the 7 hours of sleep. Obviously it’s not only about the amount, but also the quality. And the demanding day-job of having small children. I really hope you do find something that helps you a bit. In the meantime it always helped me te hear that others are having the same “problems”, that way I could “let go” and just go with the flow, assuming that it always gets better and I could do this. The best of luck to you.

        Merel wrote on June 14th, 2012
        • Thank you guys so much for your kind words. I got a bit emotional over them, as this subject is a bit taboo among my friends. I felt so pressured by them to exclusively breast feed, and when we realized that little Evey was never going to be able to latch or get suction due to her cleft palate, I felt heartsick over it. And within days, I was unable to produce enough milk for even one feeding, and I was so depressed. I thought this pregnancy/post pregnancy would have been different than with my son because I was healthier this go around. Alas. And like you, Brandon, our son was exclusively formula fed, is almost 3, 95th percentile for his height, and too smart for his own good. 😛 So I shouldn’t complain.

          Thank you all again. This is a great community, and I love that I can rely on you all for a fresh perspective. *group hug* 😉

          N3P3N7N3 wrote on June 19th, 2012
  17. I would love to do this! I have been trying to go to bed earlier, but unfortunately I watch TV or play on my phone before I settle down. It would be nice to get the hubby on board and play a card game, read, get busy, or whatever by candlelight. It makes me want to go camping even more to get away from all of the electronics and artificial light. :)

    Primal Pants wrote on June 12th, 2012
  18. A lot of professional world-class boxers follow a biphasic sleeping pattern. They get up in the morning, do some cardio and/or training, then go back to sleep for a few hours. Afterwards, they train again.

    I imagine a lot of athletes do something similar.

    Of course, there are always those contrary to the norm. For instance, welterweight champion Floyd Mayweather is a nocturnal being. He rises in the afternoon, then trains, relaxes, and sleeps in the wee hours of the morning, i believe around 7am. As Robb Wolf suggests out, electricity gives us options.

    Brad wrote on June 12th, 2012
  19. with five kids under the age of nine, I have been doing biphasic sleep for nine years now – it sucks. I guess it’s different if you wake up on your own schedule? I feel like I never fall back into a deep, restorative sleep for the second (or third) phase.

    Karyn wrote on June 12th, 2012
  20. I agree that ‘societal expectations’ about sleep patterns is a ridiculous idea from the get-go. Peoples’ individual sleep requirements are all over the map, and it’s ludicrous for anyone to make a pronouncement about blanket requirements. Some people are extreme Type A, or genetically suited to needing short rest, and need only 3 hrs/night; I need 9, but probably since I’m up 3x/night to pee (small bladder).

    But seriously, “Lifehackers”??? These people are the opposite of everything paleo/primal stands for: productivity-driven computer programmers. I can’t think of a more unhealthy group (sitting in a chair before a monitor blasting Twinkies and Red Bulls all day), nor think of a group who’s life goals reflect mine less.

    I see some economics-driven, hectic-lifestyle stressing in the above comments that seem to be the motive behind possibly embracing biphasic sleep. Sounds like one more attempt to adapt people to a stressy way of living, rather than to clean up one’s life to suit one’s inate primal needs.

    BillP wrote on June 12th, 2012
    • I think you are making a bit too many generalizations and presumptions on this.

      I’m a programmer. I code Java/HTML/JS apps all day long for a major university. On the side I’m writing an app for my local food co-op.

      I’m a big paleo fan.
      I’ve converted my wife, my son, and warmed large parts of my extended family — none of them are programmers.

      I’ve gotten a few people at my work moderately interested in paleo, two of them to a fair degree.

      Aside from paleo, we have quite a few who actively try and eat healthy, get out of doors frequently, and exercise regularly and don’t regularly eat Twinkies or Red Bulls.

      And let’s not forget that this fabulous website which Mark uses to share such awesome info with all of us was built on the backs of… “that most unhealthy group of programmers who blast Twinkies and Red Bulls all day”.

      C’mon… every segment of our society is unhealthy and in every group there are those likes us trying to become better… yes, even among us *HORRID* computer programmer types (GASP!).

      Brandon wrote on June 12th, 2012
      • Alright, alright. I shoulda put in the LOL or the :o). My apologies!

        Congrats and well-wishes on your being paleo. Hope you represent the future norm of programmers. That is a lot better than ‘productivity’ (an often-abused management concept) being the end-all.

        BillP wrote on June 12th, 2012
        • Haha. Fair enough. :)

          Incidentally, where I work quite a few of us younger-gen coders strive to lead healthier lives than many of the older-gen ones. Arguably, many go about it wrong (quite a few are vegans or workout-a-holics), but they are aware of the need to strive to be healthy. I find that encouraging.

          Brandon wrote on June 13th, 2012
  21. I think I’ll skip this one. I fall asleep usually by 9pm, sometimes earlier, and sleep like the dead until dawn.

    Diane wrote on June 12th, 2012
    • I think I fall into this category, too. I’m looking forward to two weeks of vacation to give this a whirl, though, when I don’t need to worry about mine, or anyone else’s, schedule.

      Deanna wrote on June 12th, 2012
    • Yup, I already give myself a 9-10 hr block for sleep and generally sleep straight through. I sometimes take naps in the afternoon too. Although it might be cool to be up for a couple hours when all is quiet I would then need to sleep til 10 am instead of 8.

      K wrote on June 13th, 2012
  22. This has been a natural way of sleeping during many phases of my life: as a high school student also working 30hrs a week; as a breakfast waitress and daily mountaineer; and of course as a mother of young ones.

    When I find myself in a pattern where sleep deprivation is becoming the norm, carving out a block of 1-3 hours for a nap is a life saving tool.

    yoolieboolie wrote on June 12th, 2012
  23. Without realizing it, I used to do biphasic sleeping in high school. I’d come home from school in the mid-afternoon and sleep 3-4 hours. Then I’d get up, join the family for dinner, be awake and alert for my homework, then return to bed in the wee hours for another 4-5 hours.

    It was great. Now when my occasional naps last too long I’ll consider it a split-sleep night, and still wake up refreshed the next day.

    Lesley wrote on June 12th, 2012
  24. You must have read “At Day’s Close”

    I loved that book! So much new information about how our recent ancestors experienced night time. I highly recommend it to anyone wanting more background info on this topic.

    JBailey wrote on June 12th, 2012
  25. I wouldn’t underestimate the importance of 90 minute increments. I have personally found this to be a reliable measure, and if I am woken up in the middle of one of these, I feel epecially groggy. I would recommend that each phase be a multiple of 90 minutes of actual sleep instead of four hours. And they don’t have to be equal. You could make one three hours and the other four and half.

    whistler wrote on June 12th, 2012
  26. North of age 55, most people will enjoy the benefits of biphasic sleep courtesy of their bladders. But that aside, I was diagnosed with complex sleep apnea 9 years ago, complex being the combo of obstructive and central versions of apnea. With treatment, including a CPAP, I now enjoy the benefits of biphasic sleep. 9:00 p.m. to 1:30 a.m. and 2:30 to 5:00 a.m. Not only has my overall sleep hygiene improved as compared to all of my previous adult life, my waking hours are more energetic and I find that when I wake, I WAKE. No need for stimulants or protracted periods of “revving up”. I would highly recommend a biphasic sleep regiment

    Chili Greg wrote on June 12th, 2012
  27. Very interesting. How are suppose to sleep during summer months when there is not that many hours of darkness ( dark for four hours) ? Should you sleep less?

    Linda wrote on June 12th, 2012
    • I have been wondering about that myself. If I were to sleep when it is dark and wake when its light, I would never sleep in the summer and sleep all the time in the winter. Right now, it gets dark around 10:30pm and is getting light again around 5am(or earlier). During the middle of winter it doesn’t get light until mid morning and is dark by 4pm, although much if the time the sun is hidden all day.

      KMC wrote on June 13th, 2012
  28. I am so excited to try this! For weeks, I’ve been wide awake between 3:00 – 3:15 AM. Every damn night! Doesn’t matter if I go to bed at 10 PM or 1 AM and doesn’t matter how tired I am. Then, I wrestle with the pillow until 5:00 or so when the birds announce the day. I’ve been staying up later to try to force exhaustion but maybe I’d be better off hitting the sheets as soon as the sun sets and just plan for a 3:00 am break. Heck, even if I only get another hour of semi-sleep before morning, it’d be better than what I’m doing now. Thank you for the suggestion!!

    LacyLou wrote on June 12th, 2012
  29. I just go to bed when i’m sleepy, and wake up when i’m rested. This may mean i wake at 4am sometimes – it may mean i skip a day too, lol!

    Nionvox wrote on June 12th, 2012
  30. Reading all these comments I’m amazed by how many people already have some sort of biphasic sleep pattern (and think they have a sleep problem!) I also wake up after 3-4 hours of sleep; unless I get up and do some yoga or move around I cannot get back to sleep. I always keep the lights off and just wander around the house/stretch/drink some water in the dark. I like having the place to myself, and when I go back to bed I sleep like a baby til morning.

    Gydle wrote on June 12th, 2012
  31. I have slept with this concept for sometime and I thoroughly enjoy it… That 8 hour crap is for the birds.

    Matt wrote on June 12th, 2012
  32. Didn’t I read on this site, that this 1-2 hours of semi wakeful time is when your body releases HGH ? What would the effect of actually becoming active Be?

    Greg wrote on June 12th, 2012
  33. Funny, I was just reading a particular passage in “The Primal Blueprint” book on Grok and family napping by the river in the mid-day.

    My sleep doesn’t always have me feeling rested and I often feel like I would benefit from an afternoon nap. I’ll give this a shot!

    Kevin A Goldman wrote on June 12th, 2012
  34. I usually set my alarm for 7 – 8hrs, but almost always wake up after 5 – 6hrs. I read the news and MDA in bed right after I wake up, and if I’m really tired after my hour or so of reading I’ll sleep about 90mins more.

    If I sleep more than 7 1/2 hrs in one phase I usually feel like I have the flu w/o fever and walk around like a zombie all day. If I oversleep in my second phase this also tends to happen. My most energetic days are usually when I’ve slept less than 6hrs.

    TuppTupp wrote on June 12th, 2012
  35. This really sheds light into ‘siesta’ cultures. I live in one now and could never figure out how everyone was staying up SO late and still waking hours before me… Finally I realized they all sleep in the afternoon! It seemed silly to me at first, but I guess it isn’t so crazy after all!

    Cayla wrote on June 12th, 2012
    • Good point. I made the comment below that I sleep very heavily during the winter months, requiring lots of hours, and very lightly during the summer months.
      There might be a link between biphasic sleep and the phenomena of “siestas” in warm/hot countries with lots of sunlight and heat.
      Did the Inuit have biphasic sleeping patterns? It would be interesting to find out.

      Sophia wrote on June 12th, 2012
  36. During the summer months, I tend to go to bed at 11 pm and I’m usually naturally up by 6:30 am (no alarm) cause of the sunlight.
    During the long, dark, Canadian winters, I do find myself waking up at 3 or 4 am, being alert for 30 minutes or so and then going back to sleep only to wake up a little groggy at 7 am (while it’s still dark outside).
    My desire to sleep, and sleep heavily at that, are strongest in the winter and I think that is why biphasic sleeping didn’t work for me then. The impact of natural sunlight must play a factor in this sort of sleeping pattern.

    Regardless, I’ll try out this test now that it’s summer and I feel like I don’t need that much sleep and I’ll see how I feel.

    Sophia wrote on June 12th, 2012
  37. I just thought I had middle of the night insomnia. I prefer it when my wakeful period is less than an hour, preferably less than 10 minutes and that is easier now I’m no longer worried about waking up. If I stay awake longer than I would like I just meditate and usually find I go back to sleep. In winter I like to be in bed by 9pm and up again around 7.00 or 7.30 ie dawn. In summer I go to bed around 10pm and can be up and walking the dog around 5am, and the less sleep doesn’t bother me then.
    Just as an aside. I sat in cold water last night before bed (can’t lie in it yet) and had a much deeper sleep than usual last night.

    Harriet wrote on June 12th, 2012
  38. I have always found this type of sleeping pattern to be natural, but whenever I mention it to anyone, they think I’m crazy. In the last couple of years since I started working 12-hour night shifts three times a week, this four-hour-sleep then another sleep of whatever length I need works great at keeping me from being worn out.

    Eat when you’re hungry, sleep when you’re tired. Of course real life intervenes, but just like everything else, do the best you can!

    Siobhan wrote on June 12th, 2012
  39. (Off-topic)

    News Flash! Just in: Paleo diet hits the bigtime: now featured on page 20 of the June 18th issue of the authoritative medical journal “Woman’s World” (available at your grocery store checkout line).

    BillP wrote on June 12th, 2012

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