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

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  • Little

    So that fits in terms of schedule? (I read the experiment)
    e.g. 12am-6am, then 3pm-4pm? Do you schedule your workouts in relation to when you’re sleeping? I’d love if you’d elaborate a little :)

    Thanks for all the information, I’ma totally going to hack my sleep!

  • Fabien Maurice

    Did you see my comment ?

    By the way, here is an very dense scientific explanation on why monophasic sleep is bad on the hormonal side. yeah we want science !


    • http://LifeByExperimentation.com/ Zane Claes

      Thanks for the link! (I’ve been out traveling recently).

      I’ll address my concerns more directly, as they apply to this particular forum post, now that we’re not constrained to Twitter. These are just a few thoughts after a first reading…

      1) Studying the hormones which are markers of good sleep, and not the sleep itself, is not sufficient reason to believe you’re creating safe or effective sleep patterns. The body is much more complicated than 1 dimensional picture offered by sleep hormones… they are important, of course, to use as markers, but let’s not confuse them with actual studies on the effects of polyphasic sleep. Scientific literature is riddled with the disastrous effects of taking such a restricted view of health. But, lest I be accused of the logical fallacy of “moving the goalposts,” let me be perfectly clear about what I’m looking for: a 6+ month account (if not a true study) of at least a dozen people following a specific Polyphasic schedule, and demonstrating equal or improved health across a reasonably wide panel of tests. This is by no means a rigorous or tough scientific requirement by any stretch of the imagination.

      2) I’m shocked they’d recommend using supplements, even if there’s an implied “taper-off period.” I personally found that taking melatonin leaves me groggy the next morning… after noticing this, I started doing some research, and what I found was enough to keep me away from it almost entirely (except in cases of severe jet lag, etc., and never more than twice in a week) You can find articles on Cancer.org, livestrong, etc. warning against it, but I think Mark’s Daily Apple does a decent job for an overview: http://www.marksdailyapple.com/before-you-close-your-eyes-make-sure-theyre-open/

      3) Call me pedantic, but the sheer number of typos makes me very wary of the scientific rigor of these users…

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