Home » Understanding Sleep » Sleep and Your Lifestyle » Polyphasic sleep: Can Ultra-short Sleep Phases Work For Us?

Polyphasic sleep: Can Ultra-short Sleep Phases Work For Us?

woman sleeping


Sleep is polyphasic when a person sleeps multiple times a day. In most cases, a person would have one long sleep phase (monophasic sleep schedule) followed by numerous ultrashort sleep phases or naps.

“So, how many times do you sleep? What is your sleep schedule?” Reply in most instances would be “One.” In modern society, it is what most people do. Modern lifestyle demands that. During the day we are at the job, we return late in the evening. Most of us do not have the opportunity to sleep multiple times. Sleep at night is the only option.

Nonetheless, some people sleep multiple times. In most cases, the nature of their job or lifestyle does not allow them to rest continually for long. Think of soldiers on combat duty, or a person taking part in open ocean yachting competition. They are forced to change their circadian rhythm.

As very few people follow such a sleeping pattern, it is natural for us to ask a few questions. Is it something that is good for us? Can polyphasic sleep pattern harm health?

Enter Polyphasic Sleep

Experts recommend that adults should have a sleep schedule of about 7-9 hours per day. It does not necessarily mean that it should be done in a single shift. Although, we must say that most studies on sleep are done using a single shift sleep.

However, some people want to reduce total sleep time, so that they have for time for other things. Those who support it, think that by dividing the rest into many phases, it is possible to sleep less. Polyphasic sleepers aim to reduce hours of sleep.

Although biphasic sleep is well-known to modern men (sleeping twice like in siesta), there is limited knowledge about multiple sleep pattern.

So how polyphasic sleep is practiced?

In polyphasic sleep schedule, there would be one phase of sleep that last for few hours, typically 3-4 hours. Additionally, a person would have multiple naps during the day.

Sleep studies show that one sleep cycle (non-REM and REM sleep) lasts anywhere between 70-100 minutes. Research also indicates that deep-sleep starts after about 20 minutes. Thus scientifically, 3-4 hours would be like having 2-3 cycles of sleep.

On the other hand, daytime naps should be for about 20 minutes to avoid slipping into deep sleep. Alternatively, a nap should be for about one and a half hour so that it equals to one sleep cycle.

Advocates of such a practice claim that they can get enough of rest by sleeping fewer hours a day (less than 7 hours).

How Does Polyphasic Sleep compare to Fragmented Sleep?

Question is how polyphasic sleep differs from sleep disorders like “irregular sleep-wake rhythm disorder” or “Non-24 sleep-wake rhythm disorder?

The difference is immense. Polyphasic sleep is a voluntary practice, and there is no issue of insomnia. One cannot practice this kind of sleep schedule if living with insomnia.

In the sleep disorders mentioned above, a person cannot sleep at the planned time, while feeling sleepy at other times. Unlike segmented sleep, it is a voluntary effort to increase waking hours.

It does have some similarities with insufficient sleep. As in this kind of sleeping practice, a person is still sleep deprived. It is done purposely to have more time for other activities, by reducing hours of sleep. Due to sleep shortage, a person does not have a problem in having few naps during the day to keep him or her feeling fresh.

Is Polyphasic Sleep Natural for Humans?

This is controversial. Most sleep specialists think that it is not good for humans. Humans are made to have a prolonged nighttime sleep (monophasic) or max sleep twice (biphasic) in 24 hours. Specialists believe that cutting down hours of sleep may harm health. People must have a fixed sleeping schedule, and segmented sleep is regarded as bad.

However, humans can adapt to polyphasic sleep, if living conditions demand that. So open ocean yacht racers, special combat forces, astronauts may practice it.

It is not entirely unnatural. It must be understood that the majority of animals are polyphasic. Studies indicate that as many as 86% of all mammals are, in fact, polyphasic. Rodents are an example of polyphasic mammals.

Researchers think that certain mammals evolved to be polyphasic. One reason is to avoid attack by predators by sleeping in one place for long. Another explanation is that smaller mammals cannot store enough energy; thus they need to get up often to eat food.

In conclusion, we can say that polyphasic is not entirely natural to humans, but neither completely unnatural. In certain conditions, humans may practice it without causing harm to health.

There is one study in sailors that indicated that practicing polyphasic sleep improved their performance. However, better performance does not necessarily mean better health.

Moreover, there are individual differences. Such kind of sleep is undoubtedly not for everyone. Some studies show that it may reduce immunity, lead to cognitive decline, cause metabolic dysfunction, and harm health over time.

Why Practice Polyphasic Sleep?

It is true that it is difficult to practice polyphasic sleep. It is not very natural for most of us. Moreover, it may fit into our lifestyle. Nonetheless, after practice, you may become comfortable with it. Polyphasic offers some benefits over monophasic sleep.

  • It leaves you more time for your activities– after all, the main reason for practicing it is to sleep less, to reduce sleep durations. Most of us feel the pressure of time. We never have enough time to do what we like. It is terrifying to think that one-third or more of life is spent sleeping. We cannot stop sleeping but may healthily reduce its duration.Just imagine that instead of eight hours you start sleeping for six hours. That would add almost one extra working day to your week! Now, look at this from a different angle. One extra day a week can mean prolonging your life by as much as 10%. In short, you may add several years to your life by merely practicing polyphasic sleep.
  • Live longer – first, we must accept that we are not proposing to sleep too less. Research shows that both over and less sleeping are equally bad. So if you sleep for 8-9 hours a day, you can prolong life by sleeping 6-7 hours a day.
  • Be a better learner – monophasic sleep has one major drawback. We keep accumulating stress throughout the day. During the second half of day, we all feel plunge in learning capacity. By the evening tiredness has gathered enough to make learning inefficient, there is reduced alertness.In polyphasic sleep, you may have multiple naps during the day. Each nap refreshes your brain. It means that you may remain alert even at the end of the day.
  • Better mood – some people become moody by the end of the day. Polyphasic sleep can be useful for such sensitive people. A short nap can refresh your spirit for several hours.
  • Dream more – generally, those who sleep frequently, also dream more. Polyphasic sleepers spend more time in REM sleep than biphasic or monophasic sleepers. Dreaming is useful for increasing creative thinking. Those who practice lucid dreaming would often sleep more than once.


Polysleep is not for all. Some people may have difficulty falling asleep. Such people just cannot have a quick afternoon nap. Poor health or chronic disease may make initial sleep difficult.

Polyphasic sleepers may need changing dietary habits. You may need to give up some foods that disturb sleep. Polyphasic sleepers may also need to give up drinks like coffee.

Additional Resources

  1. Ball NJ. The Phasing of Sleep in Animals. In: Stampi C, ed. Why We Nap: Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep. Boston, MA: Birkhäuser Boston; 1992:31-49. doi:10.1007/978-1-4757-2210-9_3
  2. Ekirch AR. Segmented Sleep in Preindustrial Societies. Sleep. 2016;39(3):715-716. doi:10.5665/sleep.5558
  3. Stampi C. Polyphasic sleep strategies improve prolonged sustained performance: A field study on 99 sailors. Work & Stress. 1989;3(1):41-55. doi:10.1080/02678378908256879
  4. Stampi C. Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep: Main Issues. In: Stampi C, ed. Why We Nap: Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep. Boston, MA: Birkhäuser Boston; 1992:1-20. doi:10.1007/978-1-4757-2210-9_1
  5. Capellini I, Nunn CL, McNamara P, Preston BT, Barton RA. Energetic constraints, not predation, influence the evolution of sleep patterning in mammals. Functional Ecology. 2008;22(5):847-853. doi:10.1111/j.1365-2435.2008.01449.x

The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. Read our full medical disclaimer.

[optin-cat id=6084]