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

Is “8 Uninterrupted Hours a Night” Flawed Conventional Wisdom?

Conventional Wisdom always gets an eyebrow raise from me. I can’t help it. Eventually, I take an honest look at whatever the experts are saying, but skepticism gets first dibs. I’d call it an instinct if it weren’t learned behavior from years of being burned. For example, I once took to task the most pervasive “truth” around: that everyone needs to drink eight glasses of water a day or risk kidney failure, toxin buildup, bladder cancer, and debilitating constipation. It was pretty easy to do.

But it’s not all BS. Smoking is bad for you, for example. See? I can admit when they’re right!

I wonder about the CW position on sleep, though. We generally agree on the recommended duration of sleep. “About eight solid hours” is what you’ll see everywhere, from official governmental health guides to paleo nutrition blogs (I’m sure there’s some niche community out there claiming to have “transcended” sleep, though). I’m not going to argue with around eight hours, but note the use of “solid.” What does it connote?

Unbroken. Monophasic. Constant. Actually, it both connotes and denotes these things. Solid sleep is good sleep, right? And solid sleep means sleeping for about eight hours without waking. If you wake up, you’ve got a problem. Right?

Maybe not.

For most of human history, nighttime meant darkness. Not the blueish whitish permaglow from storefronts, billboards, and headlights enjoyed by modern city-goers. Not the yellow-orange bath radiating down from street lamps on quiet suburban streets, so ubiquitous that you only notice them when they go out. I’m talking about real, permeating darkness. Camping darkness. Small country road with the car lights out darkness. For our ancestors as recently as a couple hundred years ago, this kind of nighttime darkness lasted up to fourteen hours (well, it does today, too, but we mask it with all that lighting and housing). Artificial lighting meant candles and firewood, and those cost (money or time) and don’t really replace daylight (anyone who’s stifled yawns around a campfire knows that) like today’s artificial lighting replaces daylight. People got to bed earlier – because, unless you’re rich enough to burn candles all night, what else are you going to do when it’s dark everywhere but, as Thomas Middleton said, “sleepe, feed, and fart?” – and their sleep was biphasic, or broken up into two four hour segments, with the first beginning about two hours after nightfall.

The first segment of biphasic sleep was called “first sleep” or “deep sleep,” while the second was called “second sleep” or “morning sleep.” Numerous records of these terms persist throughout preindustrial European archival writings, while the concept of two sleeps is common in traditional cultures across the globe. Separating “first sleep” from “second sleep” was an “hour or more” of gentle activity and wakefulness. People generally didn’t spend this time online gaming or surfing the web or trolling the fridge for snacks; instead, they used it to pray, meditate, chat, or to simply just lie there and ruminate on life, the universe, and everything. It was still dark out so they tended to keep it pretty mellow. Sounds nice, huh?

Robert Louis Stevenson liked the idea, too. Sleep historian (awesome-sounding job!) Roger Ekirch writes of Stevenson who, in the fall of 1878, while trekking through the French highlands on foot, alone, made a remarkable discovery. As anyone who backpacks or spends time outdoors will corroborate, Stevenson found himself drifting off to sleep shortly after sunset. He awoke around midnight, smoked a cigarette, and, only after “enjoying an hour’s contemplation,” fell back asleep. That hour, that “one stirring hour” moved him; Stevenson had never before experienced a “more perfect hour.” He had awoken not because of an interloper, a night terror, or any other external actor, but because of what he later described as a “wakeful influence [that] goes abroad over the sleeping hemisphere” and is unknown to “those who dwell in houses.”

Ekirch thinks that the Industrial Revolution, especially the invention and proliferation of cheap electric lighting, forced modern society into its current monophasic sleep pattern by making artificial lighting that really lit up a room available to everyone. People with access to light bulbs could stay awake longer in brightly lit rooms because they were no longer subject to the circadian entrainment of natural light patterns. We’ve gone over light entrainment before. It’s likely worse nowadays, since we’re not just coping with access to ambient lighting, but also loads of interactive consumer electronics (like this laptop I’m using now) blasting circadian-disrupting light directly into our faces. Whereas Owen the London chimney sweep may have flicked on the light bulb and settled down to a good book and a bottle of ale after his shift and gotten to sleep around nine or ten, Jeff the SEO analyst stays up late arguing on Internet message boards with the laptop’s blue light beaming into his very soul. Sound familiar?

It’s likely that societal expectations about sleep structure – that it’s supposed to be eight hours of unbroken, deep, heavy slumber, as everyone knows – are making problems out of what may be normal sleeping patterns. Clinicians are finding that if they can make insomnia patients understand that waking up in the night is actually normal and natural, they feel better about their condition. Because they “perceive interrupted sleep as normal,” they stop stressing over waking and are able to get back to sleep more easily. Some forms of insomnia, in which people wake up in the middle of the night, might not actually be clinical conditions, but rather the manifestation of the natural human sleep cycle trying to assert itself. Insomnia may just be a problem of perception; if you look at your “problem” in a different light as explained by Ekirch, it disappears.

Imagine the possibilities if you could work just such an hour of free waking life into your sleep cycle! You wake up and, instead of exasperatingly checking the time, making a huge huff, and angrily grumbling and tossing and turning in a vain attempt to get back to sleep…

You vigorously and enthusiastically discuss last week’s post with your significant other (whose sleep schedule is also entrained to the biphasic cycle), thus stimulating your mind and supplying a steady rhythmic stimulus to your hip extensors.

You linger in twilight mindspace, that odd world between waking and sleeping that we rarely get to explore, and ponder dreams with a clarity that the 7 AM alarm for work simply doesn’t allow.

You light a candle and quietly read for an hour or so until sleep returns.

Sleep phase entrainment isn’t that easy, though. We do “dwell in houses.” We have by and large been sleeping monophasically for probably our entire lives. Our world is the product of the Industrial Revolution, for good and for bad, and so we must work with that reality. Candles at night will help, as will camping trips when possible, and limiting excessive late night computer exposure (or installing the ever-popular f.lux) is always a good move. You can try getting outdoor light exposure during the daytime – maybe go for that hike, that walk at lunch, or that outdoor workout.

But we’ve gone over that stuff before. It’s good, but it’s been done. In light of this new (old?) information about biphasic sleep patterns, perhaps the most effective change we can make is in our perception of sleep and waking. Make like those insomnia patients and change the way you think about waking up during the night. Don’t stress and fret; welcome it. Maybe, instead of assuming that this is all a horrible mistake and your cortisol is going to spike and you’re going to crave extra sugar in your coffee in the morning next time you wake up in the middle of the night, welcome it. Ever notice how you’re not all bleary eyed and zombie-like when you wake up at 2 AM like you are at 7 AM with the alarm blaring?

I’m thinking we should all explore why that is.

What are your experiences with waking up in the middle of the night? Do you need a solid block of sleep each night, or do you just assume that’s the case? After reading today’s post, see if your next mid-night wakeup feels different.

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. I can’t remember the last time i woke up during the night, however, i do find the idea of regulating sleep patterns absolutely nauseating. I don’t want to go to bed at 9 every night. Sometimes it’s later, sometimes not at all, sometimes i sleep in till ten, sometimes 6am. Unless i eat crap, then i’m never tired from this. I think it’s great to do an all nighter from time to time, sit up listening to music or reading/writing/d1ancing(i love dancing through the night)(no computers though)). When i’m at my folks farm sleep is the best. Window wide open, sleeping naked, fresh air breezing through, the sound of the stream trickling away, the odd baa of a sheep, moonlight shards illuminating the bedroom walls and so on. I miss that terribly in the city, although i sleep just as well, but perhaps a bit less naturally if that makes sense. Yeehah!

    Rocco wrote on February 27th, 2011
  2. As a long time rescue swimmer I know the value of quality sleep, and I can personally attest that the perfect 8-hour night is not a necessity. The key to productive sleep is reaching that deep REM level of sleep which may be different for each person. I have survived many difficult times out to sea with 3 hr. sleep cycles and with entirely underestimated power nap (10-30 min). Your health and nutrition play a large roll in quality sleep as well. Supplimenting your normal diet with B-vitamins and other ingredients that provide your body healthy energy (try will help you stay active throughout the day and your body will naturally seek that deep sleep when the time is appropriate. Has anybody tried logging their hours of sleep to find their ideal range?

    Smitty wrote on February 28th, 2011
  3. Among people who live outdoors (travelling Rennies and homeless people living in tents spring to mind, seeing as how much of my early twenties was spent falling into one of those two categories) encounter this a lot. You go to bed a bit after sunset, sleep for awhile, wake up, go to to the bathroom (a hike of between 500 yards and a mile depending on the campsite) and then hang out at the fire, with people who were still up, smoke a cigarette, and then wander back to bed for the rest of the night.

    It’s a nice cycle.

    Coyote Vick wrote on March 18th, 2011
  4. In classical Luganda (the widest language of Uganda, which first encountered European influence in the late 1800s), the times of the day are named in a more qualitative manner (“the time when the fireplace goes cold”), as opposed to the modern qualitative way (“10 PM”).
    Interestingly, and in accord with this that you write above, their 11 PM was called “Ekisisimuka ekisooka”; literally: “the first stirring to wakefulness”. And midnight was called “Ekisisimuka ekisooka”; literally: “the second stirring to wakefulness”. The ancient names for the times of the day (and night; to them the day was when the light was on, and it did not cover all twenty-four hours) are very instructive into that kind of time.

    The 27th Comrade wrote on March 27th, 2011
  5. It’s rare when I have a completely uninterrupted night of sleep. When I do, they’re quite awesome. The kind of sleep that feels like you just had an hour or so of sleep, but actually had a full 8 hours of it. Those days are great, but I usually wake up at least once during the night. It’s usually around the same time(s) too. I notice if I keep the same sleep patterns all the time I actually wake up peacefully usually 5-10 minutes prior to my alarm going off. I opted for a natural alarm clock (by Philipps)which gradually lights the room up with a “natural soft light”. I have it set to birds chirping to wake me up, but it’s a lot better than the usual beeping. I also makes sure to have my windows cracked in my room to allow air to circulate. I also make sure no electronics are in my bedroom. No TV, or anything that can disrupt my sleep. It’s pitch black when I turn everything off, other than the very dim light coming from my alarm clock. These little things alone make a huge difference.

    Jonathan wrote on April 1st, 2011
  6. Hey guys,

    I found this article very interesting in that it provides good insight into why the modern-day lifestyle may not be compatible with our internal clock.

    If anyone is interested, here are two articles about polyphasic sleep:

    It’s already been pointed out that different non-developed cultures have totally different sleep preferences than us.

    The basic idea is that by sleeping in several blocks (instead of one 8 hour block) gives you more REM sleep and yet you spend less time “sleeping”.
    And, by doing this, we can achieve those so-called “sentinel” periods more often, and as such be more alert and more productive.
    Steve Pavlina from the second link explains what this meant for him.

    Point is, monophasic sleep seems to be the result of our modern lifestyle, not of our evolutionary preferences. People are able to adapt to different sleep cycles.

    Kalin wrote on June 10th, 2011
  7. Such a cool tips to sleep.

    Gender Aid wrote on June 11th, 2011
  8. I actually wanted to jot down a small remark in order to appreciate you for some of the remarkable pointers you are posting at this site. My long internet search has now been compensated with excellent content to share with my pals. I ‘d claim that most of us site visitors are truly fortunate to dwell in a really good site with so many lovely people with valuable techniques. I feel somewhat blessed to have encountered your web page and look forward to tons of more pleasurable moments reading here. Thanks once more for everything.

    Rafael Kleckley wrote on May 22nd, 2012
  9. welll I know that at the moment i’m only getting about 3-4 hours sleep a night and it’s killing me….considering that once it’s daylight I can’t get to sleep at all…and it doesn’t matter how early I go to bed at night, I don’t get any extra sleep

    Kitty wrote on May 22nd, 2012
  10. My vigorous and enthusiastic discussions with my husband are the only reason I really enjoy being up in the middle of the night.

    Meesha wrote on June 12th, 2012
  11. PBS aired a “Make Me”documentary a few days ago called “Make Me Cure Sleep”. It showed a man who claims he has only slept 2-3 hours a day all his life, and another man who gets by on 20 minute naps and regularly puts in an additional eight hours of work each night when everyone else is asleep. He was taking a drug that the documentary film maker also tried for a night, with interesting results.

    Sally wrote on February 26th, 2013
  12. I really, really like my Mindfold sleepmask. I live in a bright city and I don’t have blackout blinds, so I wear one of these to sleep every night. I layer a cotton bandana under the sleepmask for comfort and cleanliness. It can also be used for relaxation and meditation. Highly recommended; darkness is so important for good sleep hygiene! Check it out:

    Bryce wrote on May 8th, 2013

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