The Myth of the 8 Hour Sleep

medieval sleepEight hours of continuous sleep is a modern and artificial rest pattern. Some people are fortunate to have adapted to it fairly well, but for many of us, our bodies remember a different time.

Night used to be longer. Before electric light and Facebook, people went to bed earlier. Our ancestors didn’t need to condense sleep into an efficient eight hour bundle, so they enjoyed segmented sleep, or divided sleep.

Segmented sleep consisted of four hours of first sleep, then two hours of wakefulness, and then four hours of second sleep. The wakefulness period was an interesting time spent in prayer, conversation, contemplation, and sex. It was even recommended as the best time to conceive a child.

Studies of segmented sleep have detected a unique hormonal event that occur during the night-time wakefulness period. It’s a surge in the pituitary hormone prolactin, and it may improve our ability to adapt to stress.

Don’t Panic If You Wake At Night

In modern times, we have condensed the two sleep periods, and eliminated the night-time meditative state.  Condensed, continuous sleep is more time-efficient, and even if it’s not ideal for health, it’s probably good enough for most people.

Unfortunately, eight continuous hours is not always easy to do. Insomniacs can feel a lot of pressure and distress at the inability to rest in this condensed way. If you find you cannot always sleep on command, then give yourself a break. It may simply mean that you are failing to contort your physiology into a modern-day trick that is not for everyone. According to sleep psychologist Gregg Jacobs:

Waking up during the night is part of normal human physiology.

There are other ways to rest. If you cannot sleep eight continuous hours, then spread it out. Consider a daytime siesta, and  try spending more hours in bed to allow for a little natural, beneficial night-time wakefulness.

Read more about ways to enhance sleep in my Hormonal Sleep post.

Yours in Health,

Lara Briden

24 thoughts on “The Myth of the 8 Hour Sleep”

  1. In our religion ( I am Muslim) , we are encouraged to go to bed early, then wake up for prayer in the middle of the night, then go back to sleep and wake up at dawn.

    • We definitely need a total of 8 hours sleep (for the reasons you state, and for many other reasons). But it doesn’t have to be 8 continuous hours. So many people lie down for their allotted 8 hours, and then suffer because they end up not sleeping for some of it. I suggest planning to spend 10 hours in bed, and then maybe also have a nap during the day.

      • What sdbrougher probably was referring to is all the OTHER reasons that people wake up overnight, like blood sugar problems, cortisol surges, which are documented problems. The topic of your article is not the only reason people may wake up, and the sentence in this article stating “it simply means…” is simply wrong, as it discounts all of the other reasons that humans wake up.

  2. When I was serving on submarines we worked six hours on, six hours off. We would get up, wash, eat then go on shift for six hours. After the shift we would do a cleaning routine, then eat and go to sleep. It worked out to about 4 hours sleep twice a day. Time went swiftly and we were never over tired physically or mentally. Being under water we were not affected by daylight cycles. I cannot remember any time I felt as healthy as I did on that routine.

  3. I also think the way we segment sleep is our response to the unknown (the dark, the night)…to contain/control it. The night in it’s energy is very opposite to the day; whereas the day invites structure, the night is devoid of all that and is a time where one can just flow and let the night take them. Our segmenting and must have attitudes around the hours of sleep is another way to avoid surrender to the night. Surrendering to the night means it decides how you will be and sleep not you, if there is stuff you need to process you write, you paint, you follow the night river’s flow…

  4. I, as a Mammal, am active at night, without specific adaptation.
    I have been since before the age of the internet. I hate mornings. Mornings suck, and always have.
    But try as I might, I just cannot regularly go to sleep before Midnight, and am often awake until 1 or 2 in the morning.

    When on vacation and without any need to adhere to the proverbial eight-to-five, I’ll routinely establish a pattern of: Go to sleep around 2am, sleep until 11am. I am often most energetic between 10pm and whenever I head to bed and this is frequently when most of my household chores get completed.

    There have also been a ton of studies on human circadian patterns. I do not have any at hand, but there’s a lot of research that shows human beings do not operate on a 24-hour cycle when external cues are removed. We tend more to a 26-27 hour cycle.

  5. One thing missing from this article is the effects of activity level during the daytime of the people in question. Most people back then did not have desk jobs that restrict physical activity which translates to overall physical fitness. Speaking for myself, the times I had the most problem sleeping through the night was when I lack sufficient exercise. If you are sedentary and eat three square meals of fast food everyday, how you divvy up your sleep would not matter a whole lot.

  6. Michaelb stated “What mammal is active at night without low light adaptation?”. Some humans see and feel better at night. Not saying vampires, but the truth is I am one of those who don’t sleep much at night. I am lucky to get 4-5 hours a day total. I do however sleep when I can. I am no expert, however I do think there are those who adapt to night. Some people are more at ease during the day. I liked the article I just think that it is in the person to decide when the best time to sleep is. As far as it just being said in ancient text not true people have always talked about and felt out of place not sleeping at night and taking naps. Look at when you have a baby they do just what is discussed here. It is a learned behavior to sleep. You can adapt to and sleep anytime your brain will fallow what ever pattern is thrown at it. Alaska need I say more? Night 3 months people thrive there. Humans are complex and amazing so I say take it as you are don’t try to do things you cannot. No one enjoys laying down at night and staring at the fan or worrying about the next day. Your body tells you when you need sleep up you to listen or not. Sweet dreams everyone when you do sleep!!

  7. Well, I also am not so surprised. I go to bed at 10pm almost every night and awake between 3-4 almost every night for years. Then recently I was listening to Dr. Wayne Dyer and he was talking about this pattern of waking at around this time of night being kind-of a universal thing. I don’t know the truth of it for sure. But based on my experience it feels about right.

  8. I am not seeing support for segmented sleep. How is a reference in an ancient medical book confirmation of something other than cultural at that time? What mammal is active at night without low light adaptation?

  9. Please state your sources “Modern studies of segmented sleep have detected unique hormonal events that occur during the night-time wakefulness period”.

    • Sleep researcher Thomas A. Wehr at the National Institute of Mental Health did some studies in the early 1990’s that replicated prehistoric sleep patterns. Subjects were put in 14 hour dark periods, and over a few weeks they developed biphasic sleep patterns and altered levels of melatonin and prolactin.

        • Good point :-). Pre-industrial might be the better word, but I believe that “prehistoric” is the word that Dr Wehr used when presenting his research. By putting subjects under conditions with a photoperiod of only 10 hours, he attempted to duplicate what people (living at middle latitudes) would have experienced during the winter months.

  10. Interesting! Since I’ve had kids my sleep patterns follow this to a T. I astound people by sending emails at 3am (after ‘first sleep’) but they don’t realise I go back to sleep again and wake later on refreshed. My husband’s the same…

  11. This is great! I have segmented sleep almost every night, but thought it was because I have young kids. It’s good to know that history is on my side. 🙂


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