Polyphasic Paper (2005)
Polyphasic Sleeping: the Benefits of Napping
Late on a Tuesday evening I curiously read some aspiring web journalist’s weblog on personal sleep modification. It’s an intriguing concept that I’ve wondered about for a long time. Can a person reduce daily sleep by chopping up a nights sleep into short naps? Would this process adversely affect a sleeper or do the benefits outweigh the detriments? With very limited scientific research available, the best way to learn about sleep optimization is to try it. That night I stayed awake until 7am, took a nap until 7:20am and then began my day. My research had begun with a hypothesis that polyphasic sleeping is more advantageous but I needed background information on a normal sleep schedule to have a significant comparison.
One important contrast between polyphasic and monophasic schedules is the pattern of sleep stages. The easiest way to understand the five stages of sleep is to first separate them into two classes. The first stage of sleep is called Rapid Eye Movement (REM). This stage is unique, requiring a classification of its own, and it is against this stage that all other stages of sleep are compared and defined. After the first stage, a sleeper only experiences Non-Rapid Eye Movement (NREM) sleep, which classifies the last four stages, conveniently named NREM 1, NREM 2, NREM 3 and NREM 4 (Horne Why 34). However, there is still much disagreement on the duration of each stage, how many times each stage occurs in a night, the pattern these stages form, and most importantly, the actual functions of each sleep stage.
The Encyclopedia of Sleep and Dreaming claims that a sleeper will first enter the REM stage then go successively down to the deepest stage of NREM, then back up to REM, continuing this pattern throughout the night in approximately 90 minute cycles. During this process, REM sleep increases on each occurrence, while NREM sleep decreases in duration with each occurrence (Carskadon 360). Most sources agree with this point. However, as shown in Figure 1, the Complete Home Medical Guide claims that after the second occurrence of NREM 4, both NREM 4 and NREM 3 fall out of the sleep cycle (Dorling Kindersley 283).
However, the UCLA Department of Psychiatry, Neurobiology Research has published numerous papers and books, several of which agree with Carskadon. Figure 2 visualizes human sleep patterns in three age groups.
(Dorling Kindersley 283)
“Schematic representation of the cycling of human sleep stages at different times of life, with childhood broadly defined to include early adolescence, and old age including the period from the mid-50’s to the early 70’s.” (Rechtschaffen 942)
Sleep consumes about one-third of the average person’s life (Dement 23). It’s no wonder why so many people attempt to regain precious hours, days or even years by cutting down on sleep. Most people who attempt this process usually try to sleep less while retaining a monophasic schedule. That is, they cut down the number of sleep hours at night and stay awake for a longer block of time before sleeping again. By the time these people go to sleep, they have been awake for upwards of 17 hours, which is like running a marathon everyday without regular pit stops. Monophasic sleep reduction can lead to sleep deprivation, which is detrimental to both physical and mental health (Eversen 148). However, there is an alternative means of sleep reduction, which may not lead to deprivation. As a contrast to monophasic sleep, it is called polyphasic sleeping, sometimes called the überman schedule because of its promise of optimization.
The polyphasic system is a method of cutting down nightly rest to 2-5 hours by splitting up daily sleep into 20-40 minute naps, spread throughout the day. It is difficult to immediately jump into a polyphasic schedule so most people choose to begin with a modified version, which allows a 3-hour “core-session” at night and requires 3-6 twenty to forty minute naps throughout the day (Stampi 13). This is what I set out to practice, in hopes of gaining more alertness during waking hours and getting better sleep during sleep time. I settled into a core sleep time of 3 hours from 12am-3am. Then, I tried to take as many 20-40 minute naps during the day as I could squeeze in. Unfortunately, this experiment only lasted 16 days, by which time I realized that my daytime schedule was too busy to include added napping—even with the benefit of 4 extra hours from 3am-7am each morning.
For the first couple of days, I only rested during the evening naps, but soon I started to feel the effects of sleep deprivation and thereafter sleep came easily whenever I had an opportunity. Sleep deprivation came in the form of brief feelings of approaching hypothermia (hot flashes) followed immediately by hyperthermia (cold flashes), similar to the feeling of being sick. When my naps fell short and I was forced to awaken from the deepest stage of NREM, it was quite apparent that my brain was not immediately producing the neurotransmitters histamine or serotonin. It had to kick itself back into the mode of producing these chemicals. This confirms the theory that it is best to awaken from REM rather than NREM, especially NREM 4, lest a sleeper risk jarring the brain into a state for which it is unprepared. After about two weeks, I noticed it was much easier to wake up from naps and my dreams were becoming more intense, which implies that I was experiencing more REM sleep than NREM during these sessions. On this plan, I averaged 4.2 hours of sleep per day and on days that I was able to complete all of my naps, I felt more alert when awake and it was much easier to fall asleep whenever the opportunity arose.
One of the effects of splitting sleep up into naps is that the normal monophasic pattern of approximately 90 minute sleep cycles, from REM to NREM 4 and back, shorten down to 20-40 minute cycles. Because 20-40 minutes is not enough time to go from waking to the deepest sleep state successively, the human brain quickly adapts by extending the patterns across multiple naps. Some naps are entirely REM, while most naps bring the sleeper to NREM 4 almost immediately. Along with this shift, REM sleep condenses to almost nothing (Vogel 1533). Polyphasic sleeping has the advantage of shortening total REM time while increasing NREM 4 time. This is beneficial because REM sleep, being so similar to the waking state, is less necessary than NREM sleep. During stage 4 NREM sleep, the brain cuts down production of many neurotransmitters that are constantly produced during waking and REM sleep. Scientists believe this is a way for the brain to take a break from using these chemicals, thereby preventing desensitization, which would make those chemicals useless (Jacobs 189).
Reducing total REM sleep time may seem alarming to some since the function of REM sleep is not fully understood. Questions circle the scientific community regarding the need for each stage of sleep but little has yet been proven. The most current belief holds that REM sleep is responsible for maintaining and developing the body’s nervous system (Eversen 154). This has been exemplified in studies reducing or eliminating REM sleep in rats, which have been proven to die within weeks of REM deprivation. However, since the rat experiments entail keeping the creatures mobile and under stress, some speculation exists whether the rats die because of sleep deprivation or due to lack of physical rest. A counter argument to the rat test may exist in human testing. Some brain trauma patients require the removal of REM enabling brain matter. These patients have not been reported to die prematurely even though they experience no REM sleep. As long as humans get rest, REM reduction is not fatal (Siegel Why 94).
Since polyphasic sleeping changes the rate and occurrence of REM and NREM stages, it also affects dreams. Some sources claim that dreams only occur in REM sleep (Carskadon 454) while others claim that NREM dreams happen but are not remembered because they are less lucid and more chaotic (Piotrowski 387). During my experiment, I experienced several naps, which were light but full of vivid dreams. These dreams started occurring before I felt fully asleep and remained in action throughout brief awakenings. I do not recall any dreams from naps in which I was so tired that my brain launched directly into the paralysis inducing state of NREM-4 sleep. I found that it was easier to remember my dreams on a polyphasic schedule, which I attribute to the frequency increase in sleep to wake transitions. With more opportunity to experience my dreams in a semi-wakeful state, I had more opportunities to remember those dreams. I consider this a great benefit since I always enjoy my dreams.
Steve Pavlina is one of the countless weblog writers who have documented claims of success with the modified polyphasic system. He began after receiving emails from fans who have tried polyphasic sleeping and “reported higher alertness and energy, more vivid dreams and more lucid dreams, and of course lots of extra free time”. Pavlina found an optimal nap length of 25 minutes, going “5-6 hours between naps during the day and 2-4 hours between naps during the night.” Pavlina suffered known effects of sleep deprivation during the two-week adjustment period. However, as of the eighteenth day, he claims to have no sleep deprivation symptoms. On the contrary, Pavlina claims to be in perfect health, notices a lack of stress, and finds it easy to focus on tasks, productively benefiting from saved time (Pavlina).
Dr. Claudio Stampi, author of Why We Nap, Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep, founder and Director of the Chronobiology Research Institute, and the leading proponent of polyphasic sleeping hypothesizes that humans were polyphasic sleepers for thousands of years before adopting to a monophasic schedule (Stampi 38). Stampi’s research has shown increases in memory retention and analytical ability in subjects after about 2-months on a polyphasic sleeping schedule (Stampi 226). Even though skeptics believe that these results are due to a natural increase of adrenaline in test subjects (Fossett 47), Stampi’s research into napping continues unabated.
Although, little scientific research has been done prior to the last decade, Mary Carskadon notes in the Encyclopedia of Sleep and Dreaming that “one of the most striking scientific findings about napping is that humans have a biological predisposition to nap at a certain period of the day.” Many countries recognize this need and make policy to accept it into cultural normalcy. In Japan, the government recommends a 20-30 minute nap before 3pm, recognizing health and work efficiency benefits. Germans have a midday nap, closing most businesses to accommodate the habit. And, of course, Spain is famous for the Siesta, which is popular throughout many equatorial countries where weather is sometimes unbearably hot in the middle of the day (Sullivan 217). Studies have shown that adding a nap to the middle of a day in addition to a regular nighttime sleep schedule improves cognitive awareness. Carskadon leaves the subject of napping in a good light, “Daytime naps taken by otherwise healthy persons generally have more benefits than negative consequences (Carskadon 394).”
Dana Sullivan argues in How to Nap that 20-30 minutes is ideal while extending beyond 30 minutes pushes into deeper stages of sleep, making it more difficult to wake up and less likely to benefit the sleeper (Sullivan 217). However, NASA conducted experiments, successfully training participants to sleep for only 3 hours a day by taking 30 minute naps every four hours. NASA found that the subjects performed better and were more alert than they were with a solid block of 3 hours sleep (Fossett 221).
The Italian Air Force (Aeronautica Militare Italiana) also conducted experiments for their pilots. Test subjects would spend 2 hours working followed by 4 hours leisure time, repeated 4 times a day. Although sleep was allowed, subjects adopted a schedule of not sleeping at all during the first days rest period. The AMI published findings that “total sleep time was substantially reduced as compared to the usual 7-8 hour monophasic nocturnal sleep” while “maintaining good levels of vigilance as shown by the virtual absence of EEG microsleeps.” EEG microsleeps are measurable states of sleepiness, given by usually unnoticeable burst of sleep in the brain while a subject appears to be awake. Most nocturnal sleepers are heavily bombarded with microsleeps during waking hours, limiting focus and attentio (Porcu 47).
Although history does not offer proof that napping is beneficial, records contain many amusing anecdotes and rumors about nappers and short length sleepers. One of the more popular and most skewed tales is of the painter Salvatore Dali who would place a tin plate on the floor beside his napping chair, holding a spoon over the plate, releasing it to crash down at the onset of sleep. Dali claimed that he would awaken completely rejuvenated with only this minimal amount of rest (Carskadon 376). Of course, legend never accounts for times when he may have missed the plate, or failed to drop the spoon.
The Encyclopedia of Sleep and Dreaming also details accounts of researchers who first questioned the monophasic nocturnal schedule:
Thomas Alva Edison was another short sleeper, requiring less than 4 hours’ rest per day. It is said that the American inventor kept a couch in his workroom and slept only when he felt fatigued, rather than adhering to a regimented sleep schedule. Edison also investigated the sleep habits of 200 of his factory workers and not only concluded that they were getting ‘too much’ sleep but also succeeded in convincing many of them of this opinion (Hall, 1911).
Thomas Edison and Nikola Tesla, two of mankind’s most prolific inventors, were both proponents of napping as opposed to the typical monophasic sleep system of social rest. As a contemporary colleague and competitor, Tesla scoffed at Edison’s claim of sleeping less than four hours each day through napping, claiming that Edison probably slept for at least 3-hours more each night. Meanwhile, Tesla professed a mere 2 hour daily sleep requirement. Sadly for his reputation, those who personally knew Tesla claimed he would fall into sleeping trances (sometimes standing up while hotel keepers cleaned around his immobile body) (Carskadon 374). Falsifying rumors do not appear regarding Leonardo Da Vinci, who worked nearly continuously by succumbing to short 15 minute naps every four hours, cutting his daily sleep down to 1.5 hours per day (Carskadon 375).
Another modern proponent of napping is Jim Horne, who wrote an article in 2001 for the prestigious medical publication Psychologist titled “State of the art: Sleep”. In his article he claims “the average sleep length, which has been confirmed often, is 7.5 hours.” He then follows this with results from an astounding study, which implies that oversleepers have a higher mortality rate:
Longer sleepers do not have a greater life expectancy, and neither do shorter sleepers die earlier. A six-year prospective follow-up study by Kripke et al. (1998) of over one million Americans found that when daily habitual sleep exceeded seven and a half hours in apparently healthy people, mortality rates rose. Furthermore, Kripke and Marler (2000) reported that sleeping less than seven hours a day predicted no significant increase in mortality when the usual confounds such as heart disease, smoking, and obesity were removed. Surprisingly, those respondents reporting having insomnia had a significantly lower mortality risk, unless they also took sleeping tablets, when the risk rose significantly. Sleeping tablets are probably not the cause, but there are interesting implications (Horne State 302).
As of this writing, conclusive evidence has not been discovered regarding the benefits or detriments of polyphasic sleep. However, many claims have risen to the attention of scientists and laymen alike, who all desire answers. Although, yet to be proven, it would seem that polyphasic sleep can be successfully implemented and maintained to increase awareness and mental capacity while avoiding the potential lifespan shortening risks of oversleeping. When my daytime schedule can support it, I will attempt polyphasic sleeping again, documenting all of my sleep times and patterns. My hypothesis still holds that as long as a user can manage and pass the adaptation period while continuously taking the appropriate naps, polyphasic sleeping will provide more time and energy during waking hours.
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