This is a submission from my good friend Dr. Dan Pardi. I’ve received questions about polyphasic sleep for years. Well, here is a sleep experts thoughts on the topic. Enjoy! Also Dan is a PhD candidate at Leiden University working with the departments of Neurology and Endocrinology. He lives and works in the bay area and conducts research through Stanford University under the guidance of two mentors in the department of Psychiatry and Behavior Sciences.
Polyphasic Sleep – Is it magic or puffery?
In Tim Ferris’ newish book, The 4-Hour Body – An uncommon guide to rapid fat-loss, incredible sex, and becoming superhuman, Tim offers a wide-variety of recommendations to improve one’s life and conquer various physical goals. Self-exploration to promote self-awareness, I believe, is a good idea and the goal of ‘hacking’ one’s lifestyle to optimize performance holds many temptations. The term “biohacking” essentially means finding efficiencies in a wide variety health habits and goals. Do you want to do more pull ups, jump higher, or live longer? Then how do you get maximal gain for minimal effort?
Our modern-day lifestyles ask a lot from us, and pressures from work, family, and a social life (if there is any time for one) incent us to find advantages and shortcuts where we can. How can I do something quicker, better, cheaper, and with less effort? How can I get more, and how can I get more for less?
From what I can tell, Tim’s process is to seek out experts and gurus in a particular field, become their student, and then undergo a period of self-experimentation where he implements their guidance. I think Tim has a cool life. It appears he can get access to just about anyone and he’s clearly a highly productive person who has created a nationally recognized brand name for himself. He is, if anything, a masterful marketer and therefore, businesses are crawling all over themselves to have him on board. If he endorses your product or idea, you’re going to have a huge increase in visibility.
I’m going to state my overarching issue with his specific approach upfront. While I believe his process is interesting and has potential to reveal valuable information, I also believe there are many limitations to the information one can derive from self-experimentation, and this becomes especially dangerous when your n=1 study becomes hard-and-true recommendations for everyone else, especially when this relates to health-related topics. It’s more innocuous to suggest that a technique helped to improve productivity, but I think it can be perilous in other arenas. Do I think it’s wrong of him to say “hey, I experimented with this and here’s what I learned?” No. However, I become uncomfortable when someone makes big claims from extreme protocols and then not-so-subtly implies that everyone will achieve similar results. In essence, his reported experience becomes a fact and a prescription. Now, let’s talk about how I think this approach fails for one very important topic: sleep.
In his chapter entitled, ‘How to fly like a bird with only one tablespoon of almond butter a week’ oh wait, wrong chapter, in his chapter entitled ‘Perfecting Sleep – Becoming Uberman – sleeping less with polyphasic sleep,’ Tim describes a method to modifying your sleep and wake schedule so that you actually ‘need’ less sleep. He writes, ”anyone can shave six hours off their normal sleep time. If you can manage to pick a (polyphasic sleep) method and stick with it for several months, you’ll find that you feel amazing and have a seemingly unlimited amount of time during the day to get things done.” Holy bovine bells, that sounds awesome! Tim goes on to state that for him “this is the ultimate brain hack.”
What is polyphasic sleep?
Polyphasic sleep is the intentional rescheduling of sleep across a 24 hour period so that you sleep in multiple, shorter bouts across the day and night instead of one consolidated sleep bout at night (i.e., monophasic sleep). Polyphasic sleep mostly refers to sleeping more than twice (biphasic sleep) per 24 hour period and a variety of different protocols have been experimented with and described. Ferris did not invent polyphasic sleep, he has just popularized it with the success of his new book. The origination of this concept, according to this Wikipedia article, is owed to an early 20th-century psychologist named J.S. Szymanski. In other words, the concept isn’t new. The premise, stated by Ferris, is that polyphasic sleep can reduce sleep need because not all phases of sleep are necessary, and that the most beneficial phase of sleep is the REM phase: “…(during) normal sleep we experience REM for a mere 1-2 hours / night. To reap the benefits of polyphasic sleep, we’ll need to engineer things so that REM is a much higher percentage of total sleep.” He goes on to state “with monophasic sleep, you sleep for eight hours and you get about two hours of good REM sleep. This is the normal schedule most people use and it means about five hours of the night are lost to (as far as we know) unnecessary unconsciesness.” Huge red flag. Let’s say we don’t currently understand what is happening during these other stages – and, by the way, we do know about lots of important things that happen during those periods – then assuming the unknown is unnecessary is hubristic.
Not all polyphasic sleep adventurers ascribe to Ferris’ claims about reducing total sleep need. In fact, for many, experimentation with the concept is more about finding ways to gain additional sleep time and wake performance under extreme conditions. Robb recently introduced me to an ex-Navy Seal, Kirk Parsley, MD, who still works with Seals and their sleep schedules before, during, and after combat. Dr. Parsley informed me that a regular part of the Seal training is to deprive soldiers of sleep for a week in order to prepare these bad-asses for the possibility of extreme combat conditions where a full night sleep is temporarily not an option. The lesson for them is not that sleep isn’t important, but rather, this provides mental training to perform optimally under life and death situations. I believe the application of a polyphasic sleep schedule, under such situations is better than the alternative, which is less or no sleep at all. It’s been documented that naps improve performance under continuous work conditions, and in this scenarios, napping when the opportunity presents itself could lead to the relative preservation of cognitive and physical functions leading to survival. Napping during times when you cannot achieve a full amount of rest can be beneficial and should be considered.
In the heretofore mentioned Wikipedia article, several other evaluations of polyphasic sleep are described in various military contexts:
– The U.S. military has studied fatigue countermeasures. An Air Force report states: Each individual nap should be long enough to provide at least 45 continuous minutes of sleep, although longer naps (2 hours) are better. In general, the shorter each individual nap is, the more frequent the naps should be (the objective remains to acquire a daily total of 8 hours of sleep).
– The Canadian Marine Pilots in their trainer’s handbook report that: Under extreme circumstances where sleep cannot be achieved continuously, research on napping shows that 10- to 20-minute naps at regular intervals during the day can help relieve some of the sleep deprivation and thus maintain … performance for several days. However, researchers caution that levels of performance achieved using ultrashort sleep (short naps) to temporarily replace normal sleep are always well below that achieved when fully rested.
In support of Ferris’ contention that polyphasic sleep can reduce total sleep need, the Italian Air Force conducted experiments for their pilots and found some interesting results, which were then published in the International Journal of Neuroscience under the title Sleep and alertness during alternating monophasic and polyphasic rest-activity cycles. I wasn’t able to get access to this full article but the abstract is available here. This study evaluated 9 pilots under a polyphasic sleep schedule where 2 hours of activity were followed by 4 hours of rest. This pattern was repeated 4 times in a 24 hr day and was alternated with 24 hours off duty. During these 4 hour rest periods sleep was allowed. The study found that during the polyphasic sleep days, total sleep time was substantially reduced as compared to the usual 7-8 hour monophasic, nocturnal sleep. This conclusion was derived based on the observation that these pilots were not experiencing a significant degree of sudden sleep onset episodes as anticipated (contrary to expectations). However, there are signs that these pilots were getting sleepier the longer they maintained this polyphasic sleep schedule. The polyphasic sleep schedule temporarily mitigated some negative effects of sleep loss, however, it would be incorrect to conclude that polyphasic sleep obviated total sleep need. I interpret these findings to suggest that within one 24 hour period, a polyphasic sleep schedule improved alertness on a temporary basis, and likely delayed sleep need.
It is a matter of current investigation to evaluate hysteresis within our sleep wake system. Hysteresis describes the dependence of a system on both current and historical conditions. Regarding sleep, the question of high interest – given modern day, endemic sleep deficiencies – is whether we have the ability to fully recover after a period of deficient sleep. The most common scenario is less sleep during the work week and more sleep on the weekends to recover and “sleep off” the sleep debt accumulated over the week. Of great interest is to evaluate our ability to fully recover after sleep loss and to have a better understanding of how many cycles of deficiency followed by recovery can be repeated before a significant decline in cognitive and physical abilities manifest. In other words, over a weekend of recovery sleep, you may be able to recover 100% from a prior week of deficient sleep. However, if you were to immediately try to repeat this pattern, you may only be able to recover 90% of function after the next week of recovery sleep. Again, this is a matter of ongoing investigation.
In order to fully address the theory of polyphasic sleep, it’s useful to review the primary mechanisms that drive the two very different (and sometimes, not so different) states of consciousness, sleep and wake. Before I begin, I would like to state that I am a self-described skeptic. Note, skepticism is not synonymous with cynicism, which is the default rejection of new ideas (i.e., guilty until proven innocent). A skeptic is open to the possibility of anything being true, but proportions belief according to evidence. I am open to the possibility that one can limit total sleep time without acute or long-term negative consequence and I would be excited about solid evidence that supported such a finding.
Importantly, the absence of evidence is not evidence of absence, so just because a situation lacks investigational data does not make it untrue. However, one should use caution when proceeding in such a situation where the preponderance of supporting evidence is self-reports. There is an old saying by Frank Kotsonis, “the plural of anecdote is not data.” In other words, self-report has limitations and you can’t overcome those limitations by throwing volume at the problem (i.e., a boat load of case reports will not wash away these limitations). Case reports are hypothesis generating and a next step is to perform blinded investigation to add controls, limit biases, and hopefully evaluate if a significant effect likely exists. This is a long, tedious process but it is necessary. When this method is not utilized, the perception of a “real effect” – when no actual effect exists – may persist and cause many people to change their behavior. Sometimes this will simply cost you time and money. Other times, more dangerous outcomes are possible.
Additionally, incentives must also be considered. Ferris’ incentives to discover and promulgate a secret formula to give you more hours of functional wakefulness per day without a postliminary downside would certainly be a powerful influence on his judgment. His credibility comes from revealing secret formulas. These incentives could easily produce biases to filter and select information most favorable to his claim. This doesn’t mean we should write off anyone with a bias or incentive, it’s just good to make a mental note of this when reviewing someone’s treatment of a subject. Let me state my own biases upfront: I believe that a full night’s rest is necessary for current and long term health and performance.
In short, I recommend we proceed with two thoughts in mind: 1) buyer beware and 2) let’s give this a fair shake. Now let’s discuss sleep so you can make a decision about what’s right for you.
Dan Pardi is the CEO of Dan’s Plan, a ‘Quantified-Paleo’ company whose mission is to help anyone pursue optimal health in our modern world. The specific approach taken to achieve this goal is as follows: 1) Define success to understand what direction we are aim for; 2) Build a roadmap to get from point A to point B (now that we know where we are headed, how to do get there?); and 3) We help people ‘walk their path’ – are you living the lifestyle today, to be healthy today tomorrow? We focus on food, movement and sleep as three fundamental pillars of health, performance, and longevity. Visit our site and sign up for a free My Plan page to start tracking your health behaviors today.