Polyphasic Sleep: Facts & Fiction

In preparing to experiment on how to sleep less, I could not help but take a look at polyphasic sleep (note: I make a distinction between Polyphasic and Biphasic sleep here; see below for more).  If you listen to the proponents of the technique (including people whom I respect, such as Tim Ferriss), a polyphasic schedule is a way to sleep significantly less and be just as awake (if not more so).  This is supposed to be accomplished by adjusting the body’s natural rhythm to a series of short naps rather than a single block (also known as “monophasic” sleep).  In other words, instead of sleeping 8 hours at night, you take a single 20-minute nap every 3 hours (on the so-called “uberman” schedule).


Eventually I decided not to include “true” polyphasic sleep in the experiments I conducted on myself (more on this below).  The deciding factor was this article written by Dr. Piotr Wozniak, as well as this follow-up.  If you are considering polyphasic sleep I highly recommend that you read both articles in-depth before doing so.  Wozniak is a true scientist whose research on memory I have followed closely, and try as I might I cannot find a similarly reputable scientist in the polyphasic-camp to rebuke his arguments.


A few things that stick out to me:

  • The human body has adapted to follow a natural circadian rhythm (24 hour light/dark cycle).  Experiments have shown that this cycle can be expanded slightly, sometimes comfortably up to 26 hours, and anecdotes assert that some people naturally have a longer rhythm.  However there is no evidence to support the idea that we can simply reject the sleep/waking cycle that humans have evolved.  Our brains actually change their chemical balance to fit this cycle (eg, melatonin production).
  • The effects of sleep deprivation are pretty bad, and if you watch videos of people attempting polyphasic sleep most of them are very clearly suffering from these symptoms after a few days.
  • Having used tools such as the Zeo personal sleep coach to precisely monitor my own sleep cycles, I sincerely do not believe that sufficient REM / deep sleep can be fit into the nap schedules suggested by polyphasic sleep.
  • As Dr. Wozniak points out, despite sincerely looking he has yet to find a documented case of someone successfully adjusting to a polyphasic schedule for a long period of time.  Everyone who contacted him eventually gave up.


Biphasic Sleep

“Biphasic sleep” is just a fancy way of saying “afternoon nap” (“bi” = two, so you sleep two times a day).  Polyphasic sleepers are fond of pointing out that lots of famous thinkers were ardent nappers.  This by itself may not be a good reason, but it is a well-known fact that sleep is largely responsible for consolidating knowledge and generally restoring the body.  In fact, there are published research papers which make definitive claims such as “[nappers] had higher cognitive scores and lower stress levels.”  Even if it means sleeping slightly more in total each day, this sounds like a pretty good trade-off to me.


A biphasic sleep cycle

A biphasic sleep cycle


Check out my experiment on sleeping less and doing more to hear more about getting more from your sleep.

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Zane Claes
I've compiled everything I've learned about happiness and productivity. You might enjoy the posts about craftsmanship or experimentation. Below are some of the most popular posts to get you started. If you have something to share, I'd love to hear from you. - Zane

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