|Polyphasic Sleep: Facts and Myths||
Dr Piotr Wozniak
January 2005 (updated)
|This article compares polyphasic sleep to regular monophasic sleep, biphasic sleep, as well as to the concept of free-running sleep. The follow-up to this article written in 2010 is available here.|
The law of accelerating returns
We live in the times of accelerating acceleration. The Moore's Law makes the world smaller, faster, more connected and more efficient. We are now able to touch and feel Kurzweil's generalization: the law of accelerating returns . The fast-living young generation is hungry for more. More fun, more information, more accomplishment, more education and ... more waking time.
At the same time, the myth-making power of the human mind is now grotesquely amplified by the all-mighty Internet. If there is an idea that could make life better or more bearable, it quickly takes on its own Internet life as soon as it is invented. Along the rules of the memetic science, the idea grows, mutates and evolves. It feeds freely on science as well as on rumor, self-experiment, and unscrupulous sources biased by self-interest ready to trade truth for profits. It snowballs adding new pleasing facts and hypotheses as it rumbles over the unprepared minds. Like a new messiah, it drags behind new followers, advocates, apostles and die-hard guerillas ready to contribute to the ultimate victory of the cause.
Around the year 2000, a new meme cropped up in several blogs on the net: The Uberman's Sleep Schedule. Due to my interest in the role of sleep in memory and learning, it did not take long for the meme to hit my Inbox. As the concept balloons on a monthly basis, it leaves me little choice but to take a stand. This article is intended to separate facts from the myth to the best of my present ability to research the subject.
The Uberman's Sleep Schedule
The idea behind the Uberman's Sleep Schedule is to gain waking hours by sleeping the total of just 3 hours in 6 portions distributed equally throughout the day. There are many variants of the scheme proposed by those who tried to sleep along the schedule. The schedule is supposed to compress physiologically less important stages of sleep and homeostatically upregulate stages vital for mental health.
The Uberman's Sleep Schedule was proposed in this blog at Everything2. The blog reported a sleep experiment with an innocent ending: the admission that the Uberman schedule was incompatible with the experimenter's schedule and goals. Yet the meme was picked up in a Kuro5hin article in 2002. Phrased in a simple and well-structured language, this time it was noticed. Again, the post ended with "Uberman's sleep schedule is a potentially dangerous way to increase your waking hours". That did not prevent a frenzy of new followers ready to gain years of waking time. The catchy theme of the concept is that, indeed, if you succeeded in sleeping 3 hours per day instead of the prescribed 8, starting at 20 years of age, you would gain over 11 years in an average Western lifespan. The idea is very attractive. No wonder then that as such it seems to be gaining momentum.
More and more frequently, Uberman's Sleep Schedule was being referred to as polyphasic sleep (the term popularized by research and book by an Italian chronobiologist Dr. Claudio Stampi).
Polyphasic sleep is known to sleep researchers as a variant of a sleep pattern that is set in opposition to monophasic sleep. In monophasic sleep, an individual or an animal sleeps in a single block during a single wake-sleep cycle of 24 hours. Polyphasic sleep is also set apart from a biphasic sleep in which there are two blocks of sleep in 24 hours, i.e. the night sleep and the typical Latin siesta - the "6th hour nap".
Polyphasic sleep is quite widespread in animal kingdom. In a recapitulation of phylogeny, human babies also sleep polyphasically, and gradually lose their nap slots until they become roughly biphasic around the age of one. Human adults, as much as all great apes, are largely biphasic. Although a majority of westerners do not nap on a regular basis their alertness shows a slump in alertness in the middle of the subjective day. This slump can consolidate in a short block of sleep in free-running conditions.
The theory behind the Uberman's Sleep Schedule is that with some effort, we can entrain our brain to sleep along the ancient polyphasic cycle and gain lots of waking time on the way, mostly by shedding the lesser important stages of sleep (e.g. shortening Stage 1 of NREM, which seems to be just a transition state to the more "useful" stages of slow wave sleep).
To sleep or not to sleep polyphasically
Having presented polyphasic sleep as seen by its enthusiastic advocates, let us have a look at its physiological roots and implications. With every passing month, we accumulate a tremendous body of evidence of the vital role the sleep plays in memory and creativity. In addition, most of us have a good understanding that without sleep there is little chance for an intellectual accomplishment. Even more, we find it hard to stay awake unassisted for longer than 2 days. Although, super-human achievements have been well documented, where people like Peter Tripp (1959) and Randy Gardner (1965) stayed (semi-)awake for 8 and 11 days respectively, most of the mere mortals cannot even suffer through the first 48 hours of wakefulness and inevitably fall prey to slumber.
EEG measurements indicate that humans are basically biphasic. There is a single powerful drive to sleep during a subjective night, and a single dip in alertness in the middle of the subjective day. EEG measurements are confirmed by many other physiological variables such as temperature measurements, cortisol levels in the blood, melatonin level in the saliva, levels of other hormones, blood pressure, gene transcription, immune cell activity, subjective alertness, motor activity, and countless other parameters.
At the root of this periodicity is the activity of the suprachiasmatic nucleus (SCN) in the brain, which is driven by a 24 hour cycle of gene transcription changes running a classic feedback loop [ref: clock] . Tiny mutations in the genes responsible for circadian periodicity may lengthen or shorten the period of the circadian cycle. They can also lead to complete arythmicity. Many of such mutations have been studied in fruit flies and in mice. Human mutations leading to sleep phase disorders are also known (e.g. familial ASPS). However, for a vast majority of healthy humans, the length of the period is slightly longer than 24 hours. Dr Charles Czeisler has measured it to be 24.2 hours with amazingly little variation among individuals within the sample studied [ref: 24h]. The circadian cycle (incl. the gene transcription and the activity of the SCN) can be prodded and shifted slightly on a daily basis. The degree of the shift is determined by the phase response curve (PRC) and requires a very precise timing of the phase-shifting stimulus [ref: PRC]. In other words, with a stimulus such as light, physical activity, or social interaction, we can move the period of maximum sleepiness slightly. Although the precise measurements of the PRC speak of the possible shift of up to 3 hours in a single day with a single strong stimulus, it is hard, in practice, to shift one's circadian rhythm by more than 1 hour per day. We all get a little backward prod daily when we try to fit the 24 hour day. This daily resetting is painless for those who apply the principles of sleep hygiene. It occurs in the morning with light, activity, and/or stress. An increasing portion of the population use the alarm clock to do the job that should naturally by done by sunlight. This is not a healthy solution and is usually forced by our electrically-lit lifestyle with evening TV, evening reading, evening Internet, evening partying, etc. For those out of phase, it is easier to shift the sleep schedule to later hours (e.g. by activity late in the night) than it is to shift it back (e.g. by bright light in the morning). This asymmetry comes from the fact that we can consciously control the waking hours, which can only be used for a forward shift. It is easy to will oneself to stay up late. It is far harder to will oneself to wake up early. Naturally, an alarm clock can be used to accomplish the latter, but use of alarms should be avoided in chronotherapy and in healthy sleep due to disruptive effect of alarms on the progression of sleep cycles.
It is possible to shift the sleep phase. However, we do not know any biological mechanisms that could be used to reduce the length of a healthy sleep block without inducing a degree of sleep deprivation. Shifting the sleep phase has a relatively small effect on the length of the sleep block. The change is proportional to the degree of shift and has the same sign (i.e. shift delays reduce the length of subjective night sleep). Most importantly, the change reverts to baseline shortly after the shift. This illustrates the homeostatic nature of sleep control mechanisms that respond to phase-shifting stimuli by stabilizing the new sleep schedule at the new offset within a very short time (assuming little shifts generated by well-timed shifting stimuli).
Those well-defined effects of natural sleep affecting stimuli on sleep patterns lead to an instant conclusion: the claim that humans can adapt to any sleeping pattern is false. A sudden shift in the schedule, as in shift work, may lead to a catastrophic disruption of sleep control mechanisms. 25% of North American population may work in variants of shift schedule. Many shift workers never adapt to shifts in sleep patterns. At times, they work partly in conditions of harmful disconnect from their body clock, and return to restful sleep once their shift returns to their preferred timing. At worst, the constant shift of the working hours results in a loss of synchrony between various physiological variables and the worker never gets any quality sleep. This propels an individual on a straight path to a volley of health problems, which include cardiac disorders, suppression of the immune system, diabetes, gastrointestinal disorders, obesity, depression, chronic fatigue, sleep disorders, etc. Shift-workers are also at a higher risk of accidents and family problems (e.g. experiencing higher divorce rate). Shift-work should apply the laws of chronobiology to minimize the adverse effects on health. It is often better to keep workers working by night on a constant basis than to induce a regular jet lag and stress on a weekly basis by a cycle of never-ending schedule shifts.
It appears that polyphasic sleep encounters the precisely same problems as seen in jet lag or shift-work. Human body clock is not adapted to sleeping in patterns other than monophasic or biphasic sleep. In other words, the only known healthy alternatives are: (1) a single 6-8 hours sleep block in the night, or (2) a night sleep of 5-7 hours combined with a 15-90 min. siesta nap. Those numbers differ substantially across the population and there is no single recommended dose of sleep for everyone.
If a degree of pressure is exerted on the body clock, e.g. by going to sleep later than the body's optimum, the mid-day nap may serve as a compensatory buffer counteracting sleep deprivation. In such conditions, the nap may last longer than the usual 15-30 minutes. The more pressure is applied on the night sleep, the longer the siesta nap. Similar biphasic consolidation can also be produced experimentally in rats. It appears that with sufficient pressure, the nap may become longer than the night sleep, effectively reversing the sleep pattern by 12 hours. This effect confirms an important biphasic nature of the human sleep that is not fully accounted for by the present sleep models. In rare cases, individuals may learn to sleep in two blocks of 3-4 hours; however, in a vast majority of cases, the pattern in which sleep occurs in two equal blocks within 24 hours in unstable. In other words, individuals on the proportional biphasic schedule quickly fall back to long-night sleep and short siesta sleep, or back to monophasic sleep. Often, the portion of sleep that occurs during darkness takes the role of the night sleep. However, it is more likely, that this role is taken by that portion of sleep that was longer before the establishment of the proportional biphasic pattern. This again indicates the underlying physiological asymmetry between two sleep blocks in a biphasic pattern. In other words, the body remembers which sleep block is the subjective night block, even if that block happens to occur during the light period.
Through sleep deprivation, by employing the homeostatic component of sleepiness, polyphasic sleepers can increase the number of naps during the day to three. However, the pattern of one night sleep and three daily naps in highly unstable, and can be maintained only with a never-ending degree of sleep deprivation. Naturally, if you happen to use an alarm clock, you can easily run multiple "naps" during your circadian low-time during the subjective night. This is not possible during the subjective day (except in conditions of extreme sleep deprivation). To a degree, an alarm clock can also be replaced with your internal alarm (e.g. thinking "I must get up in 20 minutes"). None of "naps" executed in similar conditions will do the job of natural sleep. They are not only a waste of time, but they also contribute to dismantling your sleep control mechanisms. Dr Stampi's research on polyphasic sleep has also clearly identified the forbidden zones for sleep where naps are very difficult to initiate without substantial sleep deprivation. Those zones map well on the biphasic rhythm with the subjective evening naps preceding the core night sleep particularly ineffective for rested individuals. All the above findings inevitably lead to a conclusion that it is not possible to maintain a polyphasic sleep schedule and retain high alertness and/or creativity! As it will be shown later, practice is no less lenient in judging the impracticability of polyphasic sleep for creative individuals.
Anecdotal evidence seems to indicate that highly creative individuals perform best in a biphasic sleep pattern. However, the only valid rule of a thumb for maximizing creativity and alertness is to sleep then and only then when you feel sleepy. When this rule is applied, individuals may fall into a number of diverse schedules. They might be quite effective in any of these exemplary mono- and biphasic patterns: typical 7+2 or 6+1, long sleeper's 9+0, short sleeper's 3+1, or even 3+0, etc. Only you yourself can determine which schedule is optimum in your case. However, you can expect that if you are a normal healthy individual, this schedule will not be polyphasic. If you attempt 3+0.5+0.5+0.5, you will either be seriously sleep deprived (i.e. you will maintain the schedule only with the help of an alarm clock), or you will revert to 3+0.5, or more likely, you will fall back onto a standard 6+1 pattern. The possibility of hooking up your naps to the ultradian rhythm without sleep deprivations is a myth. Knowledge of chronobiology or an assistance from a chronobiologist can be of tremendous value here. See also: SleepChart freeware
Compression of sleep stages
One of the myths of "Uberman sleep schedule" is that it makes it possible to enter REM sleep and skip non-REM sleep stages entirely. That myth is derived from another false claim that implies a non-essential role of deep sleep. I will ignore these claims as standing in total disagreement with laboratory findings and models of sleep. Instead, let us focus on a more plausible claim of the possibility of compressing sleep stages.
It is true that people who are sleep deprived are able to enter deep sleep much faster than normal sleepers. After a period of sleep deprivation, less important stages of sleep are compressed, while the core SWS predominates. Also REM deprivation will result in REM upregulation at recovery time. Indeed, we are more effective at sleeping after we had been sleep deprived. Moreover, it is possible that the homeostatic control of sleep is not very efficient at detecting the true neural sleep need. If you look at our mammal relatives, you may be surprised that a giraffe can do well on 2 hours of sleep, while a bat may need 20. Smart and fast-learning elephants need 4 times less sleep than less brainy felines. Behavioral observations will then quickly lead us to the conclusion that the amount of sleep is not directly correlated with the amount and complexity of memory acquisition and neural computation.
We may then hypothesize that the sleep control may employ auxiliary physiological parameters that are only loosely related to the requirements of neural optimization. It is also possible, that if the night-time was not very useful as an activity time to early hominids, sleep control mechanisms might have attracted a number of additional physiological functions that might improve survival even if sleep lasted longer than what is needed for memory consolidation and optimization. Hence the possibility of all sleep mechanisms proceeding at leisurely rate with lots of added function that would not require loss of conscious awareness in the first place.
If the above thinking is correct, we might indeed be able to execute the same neural job in a shorter time given the favorable circumstances. However, little is known of the true nature of the link between neural optimization and homeostatic sleep control. Our present knowledge still seems to firmly indicate that you can maximize your creativity to sleep cost ratio only with free running sleep. In other words, there is no evidence that by playing with sleep deprivation, you can increase your creativity. The only possible exception might a tiny degree of deprivation resulting from delaying sleep by 30-60 minutes. Longer delays affect alertness beyond what might be considered a "gain". It is simply possible that between the extremes of free-running sleep and a slightly delayed sleep phase, the trade-off between (1) time gain due to sleep compression and (2) an accelerated homeostatic sleepiness might produce an optimum somewhere in between. Naturally, this tiny prod to a sleep cycle has nothing to do with the employment of alarm clocks, shattered schedule and never-ending battle with grogginess typical to those who experiment with polyphasic sleep. Moreover, even that little hypothetical intervention in the sleep cycle will inevitably result in phase shifts that may have numerous negative side effects, including, most obviously, the inability to function effectively in a society that is largely synchronized with daylight. Well-entrained free-running sleep is still your best bet for maximum cognitive performance.
Sleep and creativity: Less is more
The answer to the question "to sleep or not to sleep polyphasically" will depend on your goals and your chosen criteria. You may want to sleep polyphasically if you want to maximize the frequency of a waking activity (e.g. monitoring the instruments and the horizon in solo yacht racing). Yet you will definitely not want to sleep polyphasically if:
Paradoxically, not are you even likely to choose polyphasic sleep if you want to maximize the time spent in the waking state! Only when approaching substantial sleep deprivation can polyphasic schedule be superior to biphasic schedule in that respect.
Some people like firefighters or emergency surgeons may sacrifice their sleep for the sake of others. Most of the remaining population though will optimize their sleep for best health and best creative performance during the waking time. Polyphasic sleep is definitely not the answer to such optimization goals.
These are not the times of the pyramid of Giza when the genius of a designer had to pair up with a 50,000 drudges reduced to mere back-breaking labor. As we move towards the knowledge economy , it is the alert and creative minds that provide the basis of success in most projects. One minute of insight can be worth a century of shoveling! It might have been a single creative eureka that produced E=mc2. Probably even Einstein himself would not be able to track back the exact moment when his brain produced that formula. Nor would he be able to formulate a sure prescription for others for similar accomplishments. Human creativity is primarily a game of chance. Yet it breeds only on fertile grounds. Top-notch mind in a top-notch shape in conjunction with top-notch sleep is the best formula for more of such insights in the future. Polyphasic sleep is the antithesis of that formula!
If you scan the blogs of polyphasic experimenters you will see them choose an "engaging activity" again and again just to stay awake. Why would they prefer to meet people or go for a jogging over, for example, getting down to a mentally challenging project? Why would learning a difficult subject be a mental drag? Why would incremental reading have a torturing effect on their minds? As sports or social interactions boost the aminergic activity in the brain, these are effective counterweights to the homeostatic drive to sleep. At the same time, learning is a powerful contributor to the homeostatic sleepiness. Soporific power of learning is one of the most visible connections between sleep and memory. If you have problems with falling asleep, nothing serves as a better natural hypnotic than learning! Not just passive reading. Active learning! The best homeostatic sleeping pill I know is incremental reading. Naturally, you need a circadian component of sleepiness for the "pill" to work. Otherwise, learning (incremental reading) is, paradoxically, your best "creativity pill". It is the circadian phase that determines the positive neural feedback of learning that generates the creative enthusiasm, or the negative neural feedback of drowsiness.
There may more at stake though than just alertness, creativity, and long-term health. It is conceivable, that the sleep control centers in the brain become affected by polyphasic experiments. Researchers have noted cases where shift-work or other forced schedule patterns were able put the body clock out of kilter. Some have speculated that Peter Tripp suffered long-term consequences of his Awakeathon [ref: Tripp]. Polyphasic schedule is, naturally, far less drastic. Dr Stampi has put one Francesco Jost through a diet of 3 hours of sleep for 2 months without measurable adverse effects. Yet, looking at other neuropathophysiological processes, we might worry that it might be possible to actually kill cells in nuclei responsible for the SWS switch, REM on switch, REM off switch, etc. We know that disregarding mental hygiene, depression, excessive cell activity, hypoxia, and other neural stresses can lead to cell loss. As long as this area remains gray, playing with once sleep schedule is tantamount to dicing with once long-term ability to effectively control sleep cycles. This might be not much different from dieting, once you put your appetite control centers out of service, you are sentenced to a lifelong struggle with diets and yo-yoing weight.
Why less is more? Because by giving your brain as much sleep as it wants, you can be far more creative and productive in your waking time. Not just far more. In a polyphasic sleeper, the creativity may dip by an order of magnitude. Its like with top performance sports. Wrong timing of a dinner may cost Lance Armstrong his yellow jersey. Do not let yourself be marginalized in the race for intellectual excellence!
Probably nobody knows more about polyphasic sleep than Dr Claudio Stampi. He dedicated his life to understanding ultradian rhythms and the art of napping. His passion for the idea was born three decades ago when, as a medical student, he was also a passionate solo sailor. He studied sleep in dozens of individuals taking part in competitive sailing. He studied sleep patterns for NASA. He studied polyphasic sleep in laboratory conditions. He strapped his subject with wrist-worn activity monitors and EEG electrodes. He is a worshipper of napping as nothing counteracts sleep deprivation and fatigue better than a nap. In his work, he looks for ways towards improving alertness and survival in life-threatening situations, esp. long-distance boat racing. Yet he is not recommending the polyphasic schedule for normally functioning creative individual who can afford a full night of healthy sleep. His alleged "recommendation" is just one of those myths circulating along with the polyphasic sleep meme. Using polysomnographic tools, Stampi looks for troughs and peaks of alertness. His research tries to capitalize on understanding those ultradian rhythms and maximizing the effectiveness of napping, primarily by optimizing the timing of naps. Today he is the most recognized expert in the field.
Stampi's methods are primarily targeted at minimizing sleep deprivation. He is a biphasic sleeper himself and through his chronobiology expertise can claim proudly "I am never tired" [ref: Stampi]. When speaking about Ellen MacArthur [ref: Ellen] , he puts his research in a nutshell: "What Ellen is doing is finding the best compromise between her need to sleep and her need to be awake all the time". What a creative individual needs is no compromise. It is the uncompromising maximum of alertness, attention, and creative powers.
Stampi has shown that polyphasic sleep can improve cognitive performance in conditions of sleep deprivation as compared with monophasic sleep: Individuals sleeping for 30 minutes every four hours, for a daily total of only 3 hours of sleep, performed better and were more alert, compared to when they had 3 hours of uninterrupted sleep. In other words, under conditions of dramatic sleep reduction, it is more efficient to recharge the sleep "battery" more often. Many use this as the argument for the superiority of polyphasic sleep, while silently skirting around the fact that Stampi also notes that the performance on polyphasic schedule is still far less than that in free running sleep conditions.
Rumor has it that there were many geniuses who would sleep polyphasically. The implication is that if it worked for the greatest minds in history, it should also work for a young ambitious student with a voracious appetite to conquer the world. Yet on a closer inspection, those polyphasic stories are very hard to confirm. Somehow, the group does not include contemporary Nobel winners, presidents, or great athletes. In other words, you cannot just e-mail a celebrity and ask. All great polyphasic sleepers are dead. There are still a couple of individuals who boast in their blogs that they are polyphasic sleepers. Very often their sleep is just a stretch of the biphasic sleep definition or a combination of various sleep modes with a heavy dose of sleep deprivation. Some of those cases I cannot explain in any other way than by vested interest or a bloated ego. Even narcolepsy would not explain their napping habits. At any rate, successful polyphasic sleep cases are not in any way verifiable. Naturally, absence of proof is no proof of absence, and this section is not intended to prove that polyphasic sleep is not possible. It is the biological argument above that settles the issue. Here, I am only trying to illustrate the myth-making powers of the Internet.
As for polyphasic geniuses, the list seems to be getting longer along with the snowballing myth of the benefits of a 22 hour waking day. Currently, the list includes da Vinci, Edison, Tesla, Churchill, Benjamin Franklin, Thomas Jefferson, and even Bruce Lee. I would not be surprised if Newton and Aristotle joined soon. Perhaps even Jesus might follow up later.
I tried to find out if there is any record of the sleeping habits of the greatest geniuses in history. All I could find was rather a standard adherence to a normal monophasic or biphasic sleep, with an exception for numerous all-nighters at the time of the creative high. Only the biographers of Buckminster Fuller who I managed to get in touch with seem to confirm that his sleeping habits were quite unusual and that he experimented a lot with various sleeping patterns. In particular, while traveling and lecturing extensively, he would enter what he called a "dog sleep". That sleep, however, had nothing to do with polyphasic sleep. It was a sort of improvised mix of free-running sleep confounded by jet lag, meetings and deadlines. In other words, Bucky would catnap whenever he was tired and had an opportunity. However, if he could squeeze a sound 6 hours here and there, he would not miss the chance. This "dog sleep" did not fit any fixed alarm-clocked schedule. It was just a compromise between circadian rhythms and Bucky's hectic lifestyle.
Although even Stampi anecdotally refers to Leonardo da Vinci , Leonardo's polyphasic sleep is probably an urban myth. I could not locate any credible sources with any notes on his sleep habits, and yet da Vinci is nearly always mentioned whenever the art of napping comes into question. It seems quite strange that someone would come up with a crazy polyphasic schedule idea at the time of leisurely Renaissance life that was well-timed by the superiority of sunlight over candlelight. Allegedly, hinting at a monophasic mindset, he spoke of death: "As a well-spent day brings happy sleep, so a life well used brings happy death". Even more telling is Bandello's report on da Vinci's work over "The Last Supper". Leonardo would work continuously from dawn to dusk forgetting about food and drink. Stunned Bandello would definitely reported the round-the-clock work of a polyphasic sleeper as even more amazing. It seems to me that using a poorly researched historic case from 500 years ago as a prop in favor of polyphasic sleep is rather a dated argumentum ad verecundiam. Incidentally, da Vinci is also a name that crops up on other suspect lists: the lists of great people suffering from attention deficit disorder, or the lists of great vegetarians. The same memetic mechanism must be placing da Vinci, Jesus, Einstein, and Hitler alongside each other in a number of myths over and over again. And did you hear of "Da Vinci Code" or the authorship of the Turin Shroud?
Napoleon is not less frequently referred to in the context of napping or polyphasic sleep than da Vinci. And his case is rather easy to falsify through historical records. When compared with an artistic genius of Leonardo, it seems even more preposterous than a brilliant military commander could possibly retire for a nap during a prolonged battle or during his intense life peppered with plethora of engagements. He is indeed said to have slept little and frequently suffer from insomnia at times of great stress. He was also often interrupted by messengers that might perhaps increase his propensity to napping at daylight. Yet he was to be woken up only with bad news. The hard rule was that the good news could wait. His memoirs indicate that he did not mind dying young. Consequently, he would disregard his doctors on the matter of sleeping little and drinking buckets of strong coffee. As Napoleon's life was jam-packed with stress, his short sleep might have been a consequence of his lifestyle. Low sleep diet did not translate well to Napoleon's military skills. Some contemporaries attribute his errors at Waterloo to sleep deprivation. Yet, during slower days he would sleep for sound seven hours, waking up at 7 and often lazing until 8. Then he would yet add an nap in the afternoon. Records also indicate that at Saint Helena he was a normal sleeper, and while stress was replaced with boredom, he often slept late.
Jefferson and Franklin seem easy to falsify as polyphasic sleepers. In letters to Doctor Vine Utley (1819), Thomas Jefferson writes about his sleep habits. We can conclude that his sleep was not very regular, he would go to sleep at different times (often late into the night), he would always devote at least 30 min. to creative reading before sleep, he would fall asleep later if the reading was of particular interest, and he would regularly wake up at sunrise. In other words, expectedly, there are no traces of polyphasic sleeping in Jefferson's life. Jefferson, da Vinci, Franklin, Einstein, or Edison, are probably the most popular names on all those trumped up lists of famous people affected by X, practicing Y or believing in Z.
As for Benjamin Franklin , we might conclude that he did not hold sleep in high esteem. This we can conclude from the famous quotations such as "There will be sleeping enough in the grave" or "The sleeping fox catches no poultry". This attitude resembles the one of those who are ready to practise polyphasic sleeping today. It is also a frequent characteristic of high achievers from the times when we knew little of the biological function of sleep. Yet Franklin is even better known for saying: "Early to bed and early to rise makes a man healthy, wealthy, and wise". From this we might conclude that if he wanted to sleep less, his formula would be to get up early. Not to shred sleep into pieces. Moreover, for a high achiever with little regard for sleep, retiring for a nap might feel like a major sign of laziness or weakness. That stigma lasts until today in western culture, where napping is often considered a habit of lazybones. Last but not least, Franklin as a advocate of DST would say: "It is silly and wasteful that people should live much by candle-light and sleep by sunshine". Polyphasic sleeper definitely he was not.
We know quite a lot about Winston Churchill 's sleeping habits. As a wartime PM, his daily routine was watched closely by his assistants. Churchill could work his ministers to exhaustion by staying up late, but he would also routinely take a solid 1-2 hour nap in the afternoon. As such, he was a classical biphasic sleeper. At his house at Chartwell, his routine was quite regular. He would wake at 8, spend the morning in bed reading papers, dictating letters, etc., take a long nap at tea time, and work till as late as 3 am. He averaged 5-6 hours of sleep per day. Those words are attributed to Churchill himself: "You must sleep sometime between lunch and dinner, and no halfway measures. Take off your clothes and get into bed. That's what I always do. Don't think you will be doing less work because you sleep during the day. That's a foolish notion held by people who have no imaginations. You will be able to accomplish more. You get two days in one -- well, at least one and a half" (source). Churchill's well-drilled biphasic habits made him one of the most energetic wartime leaders. On a humorous note, F. D. Roosevelt's aides noted that after a Churchill's visit, the US president was so exhausted that he needed 10 hours of sleep for 3 days straight to recover.
Thomas Alva Edison had a love-hate relationship with sleep. Sleep researchers blame him for robbing the modern population of 1-2 hours of sleep. Workaholics like to quote him on his contempt for sleep. Advocates of polyphasic sleep claim he was a polyphasic sleeper. Indeed, Edison's contempt for sleep is well documented. Yet it can only be attributed to his ignorance. Little was known about the biological role of sleep at his time. He believed wrongly that, as with food, humans will always sleep more than necessary given a opportunity. As a natural short sleeper, he believed long sleep is a sign of laziness: "Most people overeat 100 percent, and oversleep 100 percent, because they like it. That extra 100 percent makes them unhealthy and inefficient. The person who sleeps eight or ten hours a night is never fully asleep and never fully awake - they have only different degrees of doze through the twenty-four hours". In a parallel flash of ignorance, Edison could not see much value in physical exercise. His winter home featured one of the first modern swimming pools, yet Edison never used it. He just did not share the modern view in which exercise and sleep are considered a good investment in mental and physical health. His co-workers noted that Edison actually slept far more than he would like to admit. Clearly, he would carry sleeping little as a badge of honor. He catnapped a lot, and his nap cots have been preserved to this day in Edison museums. By no means could I though find any credible evidence that Edison's napping complied to any regiment other than "nap when sleepy", which usually turns out to match a biphasic pattern. The most reliable information I could find about Edison's sleep was his own diary kept only for a short time while approaching the age of forty. From this diary we can learn a lot about his sleeping habits. He seemed rather obsessed with getting a good night sleep as his day would often start with notes on the quality of sleep. The better he slept the happier he seemed. That's quite the opposite of what polyphasic proponents claim. Instead of maximizing waking hours, Edison would rather maximize the hours in which he could use his well refreshed mind. And that's exactly what seems most rational from the point of view of physiology of sleep, mental hygiene, and productivity.
After a short stint under Edison's umbrella, Nikola Tesla became a bitter rival of his former mentor. We have all heard of the "war of the currents", but Edison and Tesla clashed in another battlefield. They tried to outbid each other in sleeping little. Tesla noted that Edison slept much more than he would want others to believe. That injects a dose of boastful personality to their own reports on how much the great inventors slept. Tesla who could indeed work throughout the night, would often crash for the entire day of sleep after his exploits. He exhibited classic signs of manic creativity, which might have been interrupted by short recuperative naps or long recovery sleep. Otherwise, Tesla was nothing more than a short sleeper. He was too busy with his pursuits to ever think of anything resembling a strict polyphasic schedule. That would be a strait jacket on his flamboyant personality.
All in all, the whole list of polyphasic geniuses seems to be lacking any credible evidence. As such it is probably a child of collective wishful thinking committed by those who would love to add waking hours to their day.
Some of the biological argument presented in this article may not be entirely suitable and convincing for teenagers, esp. those who slept polyphasically through their biology class. Let's then reword it all in baby language. Experience shows that "for dummies" sections are most popular and most effective in conveying the message. Disclaimer: the models presented below are used for illustration only and are a remote approximation of real processes occurring in sleep
A metaphor that may help you get some sense of what alarm clocks do to sleep is a comparison of NREM-REM cycles to your PC. During the day, while learning and experiencing new things, you store your new data in RAM memory. During the night, while first in NREM, you write the data down to the hard disk. During REM, which follows NREM in the night, you do the disk defragmentation, i.e. you organize data, sort them, build new connections, etc. Overnight, you repeat the write-and-defragment cycle until all RAM data is neatly written to the disk (for long-term use), and your RAM is clear and ready for a new day of learning. At waking up, you reboot the computer. If you reboot early with the use of an alarm clock, you often leave your disk fragmented. Your data access is slow, and your thinking is confused. Even worse, some of the data may not even get written to the disk. It is as if you have never stored it in RAM in the first place. In conclusion, if you use an alarm clock, you endanger your data. If you do not care about your intellectual performance, you may want to know that there are many biological reasons for which using alarm clocks is basically unhealthy. Those run beyond the scope of this article. Many people use alarm clocks and live. Yet this is not much different from smoking, abusing drugs, or indulging in fat-dripping pork. You may abuse your brain with alcohol for years, and still become president. Many of mankind's achievements required interrupted sleep. Many inventions were produced by sleepy brains. But nothing is able to change the future as much as a brain refreshed with a healthy dose of restful sleep.
Your whole sleep cycle can be explained with the clock and hourglass model. Deep in your brain, your body clock is running on a 24 hours cycle. Every 24 hours, the clock releases a sleepy potion that puts you to sleep. If you try to sleep at wrong hours, without the sleepy potion, you may find it very hard to fall asleep. All insomniacs suffers from the lack of sleepy potion. If they go to sleep too early, before they get their fix of sleepy potion, they will toss and turn. Often for hours. You need to listen to your body clock to know when it is the right moment to go to sleep.
Yet the sleepy potion produced by the body clock is not enough to put you to sleep. The brain also uses the hourglass of mental energy that gives you some time every day that you can devote to intellectual work. When you wake up, the hourglass is full and starts being emptied. With every waking moment, with everything your brain absorbs, with every mental effort, the hourglass is less and less full. Only when the hourglass of mental energy is empty, will you able to quickly fall asleep.
To get a good night sleep, you need to combine two factors:
If your sleepy potion tries to put you to sleep but your hourglass is full, you will be very groggy, tired, but you will not fall asleep.
If, on the other hand, you try to sleep without the sleepy potion while the hourglass of power is empty, you may succeed, but you will wake up very fast with your hourglass full again. That will make sleeping again nearly impossible.
Insomniacs go to sleep before the body clock releases the sleepy potion. When you wake up early with an alarm clock, you can hardly get to your feet because your body is full of sleepy potion, which begs you to go back to sleep. When you are drowsy in the afternoon, your hourglass of mental power might be almost empty. A quick nap will then help you fill it up again and be very productive in the evening. If you drink coffee in the morning, it helps you charge the hourglass and add some extra mental energy. But coffee combined with the sleepy potion produce a poisonous mix that engulfs your brain in sickly miasma. If you try to drink coffee to stay up in the night, you will feel like a horse kicked you in the stomach. That's the acme of a criminal attack on your brain's health.
Here is why polyphasic sleep will never work naturally:
If you decide to sleep polyphasically. You will have to use an alarm clock. Otherwise you will not wake up in the night. Once you use the alarm clock, you will be sleep deprived. That will make your hourglass conveniently drained of energy. Empty hourglass will make napping easier indeed. But it is the hourglass that determines your mental powers. With the hourglass empty, you will be nothing more than an empty-headed zombie.
To generate naps at equal intervals, you would have to kill the 24-h circadian component of sleepiness. You would have to kill your body clock, and prevent the release of the sleepy potion. That is not possible. The sleepy potion will be released every 24 hour and make you sleepy; however, much you fight it. The shortest natural night sleep rarely goes beneath 3 hours. Many biphasic sleepers can do well on 4 hours. Yet most adolescents may need 7 or 8 hours of night sleep to function optimally.
In healthy sleep, daytime naps are either impossible or very short. If you track your sleep with SleepChart freeware, you will see it on your own. You will see how naps tend to cluster at night time (which may be midday for you). That's exactly what polyphasic guru Dr Stampi observed with solo sailors. Remember, that for the picture to be true, you should avoid alarm clock, which naturally, is not possible in polyphasic sleep. Yet even on a forced schedule you will see regular patterns of naps being longer and more frequent at nighttime (each time your relax your discipline, oversleep, etc.). The daytime naps will be shorter, esp. at subjective evening hours (which may be midnight for you).
I hear it again and again that all biological reasoning is of no consequence because the body can always adapt to training and pressure, and that science has not yet studied successful polyphasic sleepers. Here is a reply based on the clock&hourglass model:
Healthy body clock runs a 24 hour cycle. This cycle will make you sleepy during the subjective night (which can be midday too). This is why you won't be able to wake up from your nap in your subjective night without an alarm clock. Alarm clocks are unhealthy. They prevent sleep from fulfilling its function. The choice is yours: either (1) sleep polyphasically or (2) sleep naturally and let your brain develop its full intellectual potential.
If someone tells you he is doing naps every four hours, and that the naps last 20 min. and that he wakes up naturally, you can safely fire back: "I have seen Loch Ness monster too". That will bring it home.
Disclaimer: before you offend anyone, be sure you are not dealing with someone who is affected by a sleep disorder. For example, narcoleptics fall asleep many times during a day. But that is a result of a damage to their sleep control system. It is a disease and it badly affects their productivity and their life. Narcoleptics are always sleepy.
One of the theories of the biological basis of humor says that it is generated by the sense of superiority over other individuals. Allegedly, those who are able to detect the ignorance of fellow human beings, reinforce their findings through the sense of joy and well-being. Thus seeing others doing stupid things is fun (as long as, hopefully, nobody gets hurt on the way). Supposedly, the evolutionary mechanism of poking fun at the silly ones helped humans preserve wisdom through generations long before written records were available.
In that context, if you understand the sleep control mechanisms that imply the impossibility of entrainment to polyphasic schedule, you may find studying the blogs of polyphasic sleepers extremely funny. Actually, hilarious. With clues and red flags all over the place, the bloggers keep hitting the brick wall. Luckily, those individuals usually see the light after a few weeks of pain. We should hope that nobody gets hurt in the process, e.g. as a result of driving in a sleep deprived state.
All blogs seem to roughly evolve through similar stages. They are predominantly written by males, usually young and full of youthful optimism. There is a cultish aura around the whole concept. It parallels the work ethic and self-imposed or super-imposed sleep deprivation of Aum, Branch Davidians, OTS, or Peoples Temple. This monastic appeal is accentuated by the fact that the ambitious adopters often run various forms of diets as part of their "reform". There are lots of hopes associated with the "polyphasic experiment". Those usually revolve around being able to do more, and experiencing "increased energy". The hopes are magnified by the fact that many volunteers find it difficult to get refreshing sleep in the first place. Then the struggle begins, peppered with hopeful references to "temporary adaptation phase". It all begins with grogginess, problems with waking up, and oversleeping. Tiredness mounts and the word count analysis shows that "tired" is one of the most often used words in those blogs (along "I" and "nap"). Yet the happy "polynapper" is usually able to survive the initial phase through sheer enthusiasm magnified by the availability of extra time and tripled energy to execute a major change in his life. Then the negative aspects of the experiment start showing up. Those include insurmountable sleepiness, sleeping through an elaborate system of alarms, problems with thermoregulation, negative somatic symptoms, self-blame due to repeated oversleeping, etc. Repeatedly, oversleeping occurs in the subjective night, while problems with napping occur in the subjective day. Yet "polynappers" are slow at noticing that regularity. They are happy they get the extra waking time, and yet, instead of spending it productively, they desperately look for anything to kill time to "just survive the fog". They waste precious time on futile attempts to fall asleep at a wrong time. When things do not work their way, they start experimenting with various variants of the sleep schedule. Those include: more naps, fewer naps, longer naps, shorter naps, "pseudo-naps", rigid schedule or "flexi-naps", etc. As these are usually fruitless, the concept of "core sleep" or "recovery sleep" comes into consideration. Some experimenters decide to "listen to the body". With "core sleep" and some attentiveness to one's own body rhythms, experimenters drift towards variants of biphasic sleep, and may gradually approach a reasonable sleeping schedule. Yet without understanding the basics of two components model of sleep regulation [ref: Borbely], it is very difficult to figure out one's optimum sleep timing. The difficulty is compounded by two factors: 1. conviction that polyphasic sleep model will work, and 2. loss of synchrony in circadian rhythms. As for the latter, well-entrained free-running sleep is relatively easy to understand. However, once strong phase-shifting stimuli are introduced into the system, esp. if applied asynchronously or, worse, with irregular patterns, the whole sleep control system becomes chaotic and is essentially unpredictable. In other words, even a seasoned chronobiologist might find it difficult to interpret the correlation between the timing of sleep blocks and alertness. If the unlucky experimenter does not see the biphasic light, he begins theorizing on the causes of his inability to stick to the schedule. These might be bad foods, bad hormones, lack of self-discipline, skipped naps, extra naps, troubles at work, friends, excess sleep, too much REM, too little REM, etc. The theorists speak as if one could easily guess the "level of histamine", or the duration of "Stage 3 sleep" in a nap (no blood test nor EEG needed). Falling asleep within 3-5 min. should be a breeze in a healthy free-running individual, yet polyphasic sleepers constantly battle with not being able to fall asleep fast enough while in circadian high. Equally hard, they battle with waking up from the nap while in circadian low. No wonder then that oversleeping continues, and the battle with drowsiness takes its toll. In the end, the blogger usually postpones the experiment to "better times" (after Christmas, after vacation, after the crazy period, etc.). Sometimes the blog just ends abruptly without a conclusion. Rarely does the "polynapper" admit defeat, or concludes on the infeasibility of polyphasic sleep. Few, disingenuously, claim the successful adaptation to the sleeping schedule and go on to blogging on other subjects.
Why don't we hear much of polyphasic women? Their sleep physiology is not much different from male sleep physiology. The answer lies in the links between hormones and personality. The same testosterone-derived characteristics that drive man to leadership, war, or dreams of super-human accomplishment underlie the polyphasic death wish. Those young men tend to be hungry for life, hungry for experience, hungry for accomplishment, unable to adapt to 10 pm - 5 am sleeping schedule, rebellious and ready to seek new ways towards maximum productivity. These are mostly noble characteristics. But in a mix with ignorance, they can lead to bad health, poor decision making, poor mental performance, and social frictions. These personality types are also at a higher risk of dying young. And polyphasic sleep may also have its contribution ("I have just driven polyphasically all the way from Canada"). There is only one major benefit of polyphasic sleep: polyphasic bloggers contribute to our understanding of sleep. No researcher could ethically subject that many individuals to the mental torture of polyphasic schedule.
Below I compiled a list of funniest quotes from polyphasic blogs. Those illustrate the phases of the experiment with the special focus on oversleeping and alertness. Naturally, the list is very selective and out of context. Bloggers often claim they feel great, the method works, and they plan to continue indefinitely. Yet interwoven with the enthusiasm are red flags that amazingly keep passing unnoticed. A few blogs even scream great success. I won't quote or link to these as I found them quite disingenuous, and transparently carrying a hidden agenda. These would dilute the truth and hype a potentially hazardous habits. If you care, you can easily find these on your own.
While reading, keep in mind the ever-mutating list of myths surrounding the polyphasic sleep schedule:
Cream of the crop
Disclaimer: This section is added for humorous effect only. It proves little about polyphasic sleep. If you seek evidence for or against polyphasic sleep, read To sleep or not to sleep polyphasically or at least: Polyphasic sleep for dummies.
"Theories" (warning for skimming readers who are out of context: those "theories" have nothing to do with science!)
Finally, a blog quote that falls out of the comedic category:
Even though it is not nice to poke fun at anyone, I hope I do it for the right cause. After all, ignorance and mental flops happen to everyone, incl. the greatest geniuses of history. Those young man show many characteristics that will make them successful in life: perseverance, curiosity, willingness to experiment through pain, voracious attitude, zeal for action and change, etc. Many of those quoted bloggers will go on to do great things in life. Naturally, I do not believe that will happen on a polyphasic sleep schedule.
Circadian cycle and the PRC
- PRC: Sat Bir S. Khalsa, Megan E. Jewett, Christian Cajochen and Charles A. Czeisler (2003), A phase response curve to single bright light pulses in human subjects . J Physiol 549.3: 945-952
- 24h : C.A. Czeisler et al. (1999), Stability, Precision, and Near-24-Hour Period of the Human Circadian Pacemaker, Science, Vol. 284. no. 5423: 2177 - 2181
- Borbely : Processes Underlying Sleep Regulation
- 28: Human biological clock set back an hour
Molecular and neural basis of circadian rhythms
- biol: Pace-Schott, E. F., & Hobson, J. A. (2002). The neurobiology of sleep: genetics, cellular physiology and subcortical networks. Nat Rev Neurosci, 3(8), 591-605
- switch: Clifford B. Saper, Thomas E. Scammell and Jun Lu (2005), Hypothalamic regulation of sleep and circadian rhythms. Nature 437, 1257-1263
- clock: Molecular mechanism of biological clock
Claudio StampiSleep deprivation
Further reading at supermemo.com