Friday, August 23, 2013

The Segmented Sleep Cycle

Sleeping garbage collector
photo by Harald Grove

Do you have trouble sleeping?
 Do you wake up in the middle of the night and can’t get back to sleep?
 Are you exhausted when the alarm goes off every morning?

Sleeping pills
photo by Brains In the Head

You need to buy the latest over-the-counter chemical du jour, blessed by the pharmaceutical industry and guaranteed to put you in a coma for 8 hours!!!

Or how about a direct injection of caffeine to kick-start to your morning??!? 

Sleepy kitty
photo by dominiqs
Or maybe you just need to learn how to sleep...
That we are not much sicker and much madder than we are is due exclusively to that most blessed and blessing of all natural graces, sleep.
Aldous Huxley


I’ve been trying to remember all the times that I’ve ever had a really good night’s, maybe a handful of times in the last decade.  For as long as I can remember I’ve been a light sleeper and very, very rarely remember my dreams.  Waking up two, three or four times a night is not uncommon and I tend to be groggy in the mornings (perhaps you’re familiar with this feeling, too).
And it’s not like I’m burning the midnight oil.  I’m a good boy; I try to get the recommended 7 to 8 hours of sleep every night, generally bedding down between 11pm and midnight, then jolting awake to the 7 o’clock alarm.  There’s no snacking before bed.  No running around the block to get my blood pumping.  Why am I so freaking tired all the time?
As it turns out, I may just be doing it wrong.

And Miles To Go Before I Sleep...

Back in the early 90’s, a psychiatrist named Thomas Wehr conducted a sleep experiment in which 14 people were kept in darkness for a month.  These human guinea pigs (more like moles, I guess) were allowed to sleep as often and as long as they wished throughout the experiment.
On the first night, the subjects averaged about 11 hours of sleep, most likely making up for the sleep debt they accrued before beginning the study.  As the weeks wore on, though, an interesting pattern emerged – the people were sleeping for 8 hours per night, but not consecutively.  Typically each person would sleep in two distinct blocks, first sleeping for about 4 hours, then waking for an hour or two before returning to sleep for another four.  It turns out that Wehr had stumbled upon the normal, natural sleeping pattern of humans prior to the Industrial Revolution.  This pattern is known as bimodal or segmented sleep.

The Segmented Sleep Cycle

After 15 years of research into the topic, historian A. Roger Ekirch released a paper in 2001 citing over 500 references to this two-phased sleep in historical texts.  From diaries to court records and even a reference in Homer’s The Odyssey, the two distinct blocks known as “first sleep” and “second sleep” seemed to be common knowledge in the pre-industrial world.
Woman with lantern
photo by 75joannas
Before the advent of modern lighting (especially the electric light) nighttime was reserved solely for ne’er-do-wells and scoundrels of society.  Candle wax came at a premium and the rich folk who could afford it preferred to stay in the safety of their homes until daybreak.  So as darkness fell, people would retire to the bedroom and begin their first sleep, waking again after a few hours to relieve themselves, smoke tobacco, pray, write about their dreams or make the sexy time (but not all at once).
In fact, making love at midnight (and, presumably, piña coladas and getting caught in the rain) was a common and well-accepted activity for the period between first and second sleeps.  One 16th Century doctor’s manual from France even professed dorveille ("[the time] twixt sleep and wake") as the best time for sex because the couple would get more enjoyment after a good rest than immediately after a day’s labor.
So what happened?

Here Comes the Sun

Old street lamp
photo by Bogdan Migulski
As lighting improved over the 17th and 18th Centuries, people began to use night as a time for all kinds of activities.  Advances in both home and street lighting meant people could stay awake until all hours of the night socializing, doing chores, running errands or having sex, which eventually left only a single 8-hour chunk for sleeping.  Sleep went from a natural, normal cycle of rest to an afterthought and by the early part of the 20th Century, the idea of bimodal sleep had been almost entirely forgotten.
No surprise then that as we moved away from our natural sleeping pattern we began to see an increase in sleeping disorders.  Our bodies have evolved to work in rhythm with the sun and modern lighting, while a huge benefit to the productivity of society, has interrupted our normal sleep cycle, causing a vast amount of both direct and indirect problems (damn you, Thomas Edison!).  Anxiety, stress, fatigue – poor sleep does terrible things to both mind and body, but is highly under-appreciated in today’s world.


Though the notion that we need 8 hours of uninterrupted sleep is still widely held, there’s a growing number of sleep scientists who believe the segmented sleep cycle is the normal, natural behavior for us humans.  In addition, many people who have started living by the segmented sleep pattern have reported not only a greater sense of wakefulness, but also a significant increase in mood and much more vivid dreams.
If you have a couple of minutes, I’d like you to check out this blog entry from a guy who went without artificial light for a month both during summer and winter months.  He details all of the benefits and drawbacks of his little experiment and I found it quite eye-opening.
...the downsides of cheap light may be as serious as the downsides of cheap food.  Artificial light disrupts our circadian rhythms, prevents the production of melatonin, increases the risk of certain cancers including breast cancer and prostate cancer, and can generally wreak havoc with our health.  My guess is that artificial light is causally linked to obesity, depression, immune disorders, and cancer, not to mention daytime tiredness.
I’m guessing you probably don’t want to go without artificial light (and neither do I), but I think we, as a society, need to better understand how our sleep patterns affect our bodies.  And I don’t know about you, but I’m tired of being tired so I’m going to give it a shot!  Look for another article in a couple of weeks detailing my experience with segmented sleep...should be interesting.
One more thing before I go:  here's a great video I'd like you to watch.  It's short, but a pretty good overview about the natural human sleep cycle.  Take a look...

If you decide to try this segmented sleep thing, too, let me know how it turns out.  I’d love to hear from you!
Sleep tight!
- Nate
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