Is Polyphasic Sleep Safe?

Sleeping in a series of shorter periods instead of one long sleep, can be an intentional practice called polyphasic sleep. It has its fans and its detractors, but is polyphasic sleep safe? Let’s see what the research has to say.

By Sheryl Grassie

The importance of getting enough continual sleep is well documented. In contrast to this conventional wisdom, a biohacking movement has been advocating for multiple short-duration sleeps called polyphasic sleep in an attempt to increase productivity and available work time. Is polyphasic sleep safe? Are their benefits? Is it harmful?

The Debate

Although research is still in process, polyphasic sleep has gained enough support to form a society, the Polyphasic Society, that is a great resource for all things polyphasic. They claim amazing health benefits and have some science to back it up. In contrast, many doctors and sleep professionals are more than dubious and go as far as to strongly caution against polyphasic sleep schedules, calling them unsafe and even dangerous.

Who is right, and how do we know what to believe? Understanding more about different sleep cycles, natural or constructed, as well as different outcomes and different schools of thought may help you make up your mind regarding whether or not polyphasic sleep is safe or something you might want to try.

For the most part, we can say that people don’t come to polyphasic sleep naturally but have to structure their sleep and force a chosen schedule for it to become part of their routine. Some might argue that this alone does not bode well as it goes against nature, circadian rhythms, and the innate way we sleep. Others might argue that they have found a way to separate the wheat from the chaff in regards to sleep. You will have to decide for yourself, but here are some things to consider.

Sleep Patterns

Most of us engage in one long sleep nightly. Some individuals, and some cultures, add a nap. Naps are common, considered healthy, and even expected for some age groups like babies, young children, and seniors. Other choose shorter or more spaced out sleeping throughout a 24 -hour period.

There are benefits from sleeping in one stretch, from napping in addition to the one stretch, and from only sleeping in multiple small installments. There are two primary variables to consider: pattern of sleep and amount of sleep overall. Here are some particulars on the different options.

Monophasic Sleep

As the name implies, it is a singular phase of sleep during a 24-hour period. This is usually an overnight stretch of 7-9 hours and is considered the accepted or “normal” way to sleep in 21st century societies. Research suggests it has become the norm but may not have always been the case. When work became mechanized during the industrial revolution, a long and continuous workday did not allow for split sleeping and transformed previous sleep schedules that might have included a nap.

Prior to the industrial revolution, people slept in shifts of different kinds. Research suggests that we did not always sleep a straight 8 hours and may, in fact, have slept for roughly 4 hours after sunset, a first sleep, only to wake for several hours and then go back to sleep for another 4 hours, or second sleep, with the total amount being similar to what is recommended today between 7-9 hours.

In the literature of the 16th and early 17th century, in particular, and as far away as Africa, the terms “first sleep” and “second sleep,” were found to be common. There were cultural edicts regarding these sleep cycles, like after first sleep was the best time to conceive a child, or an understanding that between sleeps was a great time to work, sew, or have sex.

In the 200 years between the end of the 17th century and the beginning of the 20th century, references to first and second sleep started to disappear from literature, medical texts, and even court records, until they essentially vanished. Historians believe this is indicative of a change in expectations regarding people working work longer shifts. Sleeping in one long stint was the only option to acquire enough sleep, and the practice was adopted world-wide.

Biphasic Sleep

Biphasic sleep is a reference to sleeping in two shifts. This would include the above mentioned first and second sleep pattern, it would include the sleep of cultures that take a long siesta to get out of the heat and then sleep for a moderate duration overnight, and it includes sleeping overnight but taking a daytime nap of varied length. Most of these options, again, add up to the recommended 7-9 hours of sleep.

Biphasic sleep is not uncommon. Latin American and Mediterranean cultures have routinely taken naps of up to 90 minutes before returning to their day. 90 minutes is the approximate amount of time to go through one complete sleep cycle and may have been a natural need when napping.

Adding a short daytime sleep is considered advantageous and there is research based evidence that naps have many health benefits. They increase memory, support learning, can improve mood, and enhance performance. This biphasic way of sleeping is a generally accepted variation of one long overnight sleep.

Polyphasic Sleep

The most controversial of the three patterns profiled here, polyphasic encompasses multiple sleep patterns where a person can sleep from 4 to 6 times per day. There are different versions that might include one longer sleep, from 90 minutes to 6 hours, and then a series of short 20 or 25-minute naps spaced out during waking hours.

Another version of polyphasic sleep eliminates the longer sleep period altogether and recommend taking only shorter naps at regular intervals. These patterns of sleep can result in anywhere from 2 or 3 hours to 8 hours of sleep in a 24-hour period. The polyphasic sleep patterns are the only one that can intentionally result in far less than the recommended 7-9 hours in a 24-hour period.

Polyphasic sleep is not considered natural and, in general, is not recommended by medical or sleep professionals. It must be conditioned into practice with at least a two-week period to reset one’s circadian rhythm. Even supporters of this way of sleeping describe this inculcating period as grueling. Supporters of this pattern, however, believe it is worth it. They espouse that because of these shorter sleep periods, the body is more tired and falls more directly into REM and slow wave sleep. They believe the other stages of non-REM sleep are unimportant and in a classic biohacking fashion are attempting to utilize what benefits the body most. Also, the additional time gained can then be used for more important waking endeavors.

Is Polyphasic Sleep Safe?

You can definitely find arguments on either side of the issue. Some supporters claim it is a far superior way to sleep, others caution against its potential dangers. Here are some pros and cons for your consideration.


More Time

A big benefit of this sleep pattern is the ability to have more time, accomplish more, and potentially make more money. Supporters cite high performers from the past like Thomas Edison and Nicola Tesla who slept as little as 1.5 hours nightly, and contemporary leaders like the CEO’s of Yahoo, Twitter, and Square, or celebrities like Marth Stewart and Jay Leno.

The polyphasic movement believes that less sleep and more strategic sleep can be a route to greater accomplishment. Time is a commodity in our culture and polyphasic sleeping may enable you to have more of it.

Increase Slow-Wave Sleep

If in fact you can structure your sleep so you are tired and drop directly into a slow wave sleep state including REM, the theory goes that you will have more proportionate sleep time in these deeper healing states. This could possibly increase memory, be good for brain health, and contribute to restorative health throughout the body.

Lucid Dreaming

With polyphasic sleep, it is believed you are likely to have more lucid dreams. These are dreams where you are aware you are dreaming and can actually manipulate or change the outcome of the dream. There is a branch of psychology that is called lucid dreaming therapy, and it is used to work through things in the subconscious and eliminate nightmares and other psychological disturbances.

Mental Clarity

How do all these inventors and CEO’s accomplish so much with so little sleep? The lack of sleep puts them in a heightened state of mental clarity, and they are able to think more clearly, remember more readily, and have increased mental acuity. This is a large part of the draw to engage in polyphasic sleeping. Who wouldn’t want to in essence to be smarter and more able to function mentally?


Sleep Deprivation

Many experts will argue that for most people sleeping less than the recommended 7-9 hours will result in sleep deprivation. Sleep deprivation can have many negative effects on physical and mental health including heart disease, arthritis, diabetes, obesity, anxiety, and depression to name a few.


If you force yourself to sleep in small amounts, it can cause a type of mania. A hallmark of bi-polar disorder, states of mania can cause an individual to do risky things and the heightened state is often followed by a depressive crash. Mood stabilization is considered a far healthier way to live.

Mania, however, may in fact be the hyper mental focus we see with very accomplished people who sleep very little. In theory this might have a negative effect on health and longevity, but both Edison and Tesla lived into their mid-eighties, quite elderly for their time.


Polyphasic sleep is associated with sleep deprivation, and it can cause changes in hormone levels. These changes can result in increased appetite and issues with blood sugar. In addition to metabolism, it can affect heart rate and blood pressure, and suppress specific hormones that regulate the thyroid, growth, and aging.

Societal Norms

Another possible detractor of this type of sleep schedule is how it works with your life and society. Is your boss cool with you napping at work? Can you comfortably stop in the middle of a dinner party and tell your host you need to take a nap? Working a polyphasic sleep schedule around normal life activities could be very challenging.


Is polyphasic sleep safe? A conservative answer to this question would be yes, if you still get around 8 hours of total sleep each day. Polyphasic sleep schedules can be as little as 2 hours a day, or up to 8 hours. For a few select individuals, the kind that thrive on extreme sports, they may be able to make 2 hours work, but for the general public, this would result in sleep deprivation and all kinds of health issues. If you are interested in the many possible benefits of polyphasic sleep and are aware of the downsides, it may be worth a try.

Comments (0)

Leave a Comment

Your email address will not be published. Required fields are marked *