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Most people follow a monophasic sleep pattern, meaning they sleep one time per day. Alternatively, many people sleep twice per day in a biphasic sleep pattern. People who sleep biphasically usually have one long period of sleep at night and a nap in the afternoon.

Polyphasic sleep is less common and involves sleeping more than twice per day. Some people like soldiers follow a polyphasic sleep out of necessity, while babies naturally fall into this pattern.

Since at least the 1940s, people have been experimenting with using polyphasic sleep as a way to reduce time spent in bed. Some “sleep hackers” claim to be able to thrive mentally and physically off as little as 2 to 3 hours of sleep per day spread over a series of naps. However, scientific evidence doesn’t support these claims.

Let’s break down some of the most common polyphasic sleep patterns and look at whether they’re safe or beneficial.

Polyphasic sleep refers to sleeping in more than two segments per day. Following a polyphasic sleep pattern doesn’t necessarily reduce the total number of hours you sleep, but many people adopt polyphasic sleep as a way to reduce their overall sleep time and maximize their wakeful hours.

Even though monophasic sleep is the norm for humans and other primates, the vast majority of mammals follow a polyphasic sleep pattern.

There are numerous ways to adopt a polyphasic sleep schedule. For somebody traveling across multiple time zones, it might involve resting during layovers or flights. For a student cramming for an exam, it might involve a series of short naps whenever they lose focus.

A number of set polyphasic schedules have become popularized on the internet among people looking to “hack” their sleep. The following are three of the most common.

Dymaxion schedule

The Dymaxion sleep schedule involves taking four 30-minute naps every 6 hours for a total of 2 hours of sleep per day.

This sleep schedule first appeared in a Time article in 1943, in which the American architect Buckminster Fuller claimed to have followed this sleep schedule for 2 years.

He claimed that the reason he eventually switched back to a monophasic sleep schedule was because his business associates “insisted on sleeping like other men.”

Example:

12:00 am to 12:30 amNap
12:30 am to 6:00 amAwake
6:00 am to 6:30 amNap
6:30 am to 12:00 pmAwake
12:00 pm to 12:30 pmNap
12:30 pm to 6:00 pmAwake
6:00 pm to 6:30 pmNap
6:30 pm to 12:00 amAwake

Uberman schedule

There are several variations of the Uberman schedule. One common variation consists of taking a 20-minute nap every 4 hours for a total of 3 hours of sleep per day.

Another variation consists of eight naps throughout the day. In a third variation, the naps are 30 minutes each instead of 20 minutes.

Example:

12:00 am to 12:20 amNap
12:20 am to 4:00amAwake
4:00 am to 4:20 amNap
4:20 am to 8:00 amAwake
8:00 am to 8:20 amNap
8:20 am to 12:00 pmAwake
12:00 pm to 12:20 pmNap
12:20 pm to 4:00 pmAwake
4:00 pm to 4:20 pmNap
4:20 pm to 8:00 pmAwake
8:00 pm to 8:20 pmNap
8:20pm 12:00 amAwake

Everyman schedule

The Everyman schedule consists of one 3-hour block of sleep per night with three 20-minute naps spread throughout the day. Several variations have sprung up in which the length of the naps and nighttime sleep vary.

Example:

12:00 am to 3:00 amSleep
3:00 am to 8:00 amAwake
8:00 am to 8:20 amNap
8:20 am to 1:20 pmAwake
1:20 pm to 1:40 pmNap
1:40 pm to 6:40 pmAwake
6:40 pm to 7:00 pmNap
7:00 pm to 12:00 amAwake

There’s no scientific evidence that adopting a polyphasic sleep schedule is advantageous to a monophasic or biphasic sleep schedule. There’s also no evidence that your body will functionally adapt to an extremely limited amount of sleep.

Polyphasic sleep may be beneficial in situations when the alternative option is not sleeping at all. Many solo sailors follow a polyphasic sleep schedule leading into a race to help them manage limited sleep while racing.

Napping during periods of sleep deprivation can help ward off sleepiness caused by sleep pressure. Sleep pressure is the feeling of drowsiness that increases the longer you stay awake.

In a 2017 study, researchers examined the sleep schedules of 61 undergrad students and compared their sleep habits to their academic performance.

The researchers found that students with irregular sleep schedules had disruptions in their circadian rhythm equivalent to traveling westward two to three time zones. Polyphasic sleep was associated with poorer academic performance even when students slept the same number of hours.

Polyphasic sleep schedules that reduce your overall number of hours spent asleep can lead to the same health risks as other forms of sleep deprivation.

Chronic sleep deprivation puts you at risk of developing:

There’s no evidence that polyphasic sleep is linked to any physiological benefits. Polyphasic sleep schedules that severely limit sleep are difficult to sustain and can cause the same health consequences as other types of sleep deprivation.

If maintaining a regular sleep schedule is an option, it’s likely best to avoid polyphasic sleep.

If you’re going to start a polyphasic sleep schedule, it’s best to start on a schedule that doesn’t limit your total number of hours of sleep. For instance, if you’re currently sleeping about 8 hours per night, you can try a sleep schedule consisting of one 6-hour sleep session and two 1-hour naps.

It’s also important to realize that polyphasic sleep schedules that limit sleep are usually only sustainable for a short period.

Biphasic sleep refers to sleeping in two segments. It’s commonly implemented in many cultures around the world with the addition of a “siesta” in the mid-afternoon.

Anthropological evidence suggests that biphasic sleep may have been the norm in many cultures before the industrial revolution. It’s thought that many people would sleep in two shifts with a 1- to 2-hour break between.

The Centers for Disease Control and Prevention(CDC) recommends that adults get at least 7 hours of sleep per night. Many people, especially those involved in vigorous physical activity, may need even more.

Teenagers, children, and babies have higher sleep requirements than adults.

AgeCDC recommendations
0 to 3 months14 to 17 hours (including naps)
4 to 12 months12 to 16 hours (including naps)
3 to 5 years11 to 14 hours (including naps)
6 to 12 years9 to 12 hours
13 to 18 years8 to 10 hours

Many polyphasic sleep schedules severely limit the number of hours of sleep you get per night. Even though some people claim that your body will adjust to limited sleep, there’s no scientific evidence that your body will functionally adapt to limited rest.

Some people with a rare mutation of a gene called ADRB1 may be able to function on less than 6.5 hours of sleep per night without any detrimental health effects.

At this time, there’s no evidence that adopting a polyphasic sleep schedule that limits your total amount of sleep is effective for maintaining optimal mental and physical health.

Polyphasic sleep may be beneficial in situations where it’s not possible to follow a regular sleep schedule, like when you’re traveling. Taking a series of short naps may help offset some of the effects of sleep deprivation.