Polyphasic Sleep

Definition

Polyphasic sleep involves several short sleep periods, generally with one longer period lasting a few hours, supplemented with short, 20-minute naps throughout the day.

What is Polyphasic Sleep?

Most sleep experts recommend sleeping between 7 and 9 hours per night. But some people simply don’t want to spend this much time asleep. Enter polyphasic sleep, a new trend involving much shorter sleep periods spread through the day and night.

Both monophasic sleep (one 6-9 hour sleep phase) and biphasic sleep (two 3-4 hour sleep phases) are historically common and biologically normal for humans. Research has shown that both types of sleep routines can yield healthy, robust sleep architecture with adequate overall rest.

By contrast, polyphasic sleepers spend between two and seven hours asleep in total, generally with one longer period lasting a few hours, supplemented with short, 20-minute naps throughout the day. Advocates of this practice say the body adapts to this schedule by entering REM sleep more rapidly, meeting the body’s need for sleep in less time.

How Does Polyphasic Sleep Differ From Fragmented Sleep?

Polyphasic sleeping patterns may resemble those of Non-24 sleep wake rhythm disorder or irregular sleep-wake rhythm disorder. However, polyphasic sleep differs from these sleep disorders because polyphasic practitioners restrict their sleep in order to increase productivity, while people with sleep disorders aren’t intentionally restricting their sleep.

In practice, polyphasic sleep may be most similar to insufficient sleep syndrome (also called behaviorally induced insufficient sleep syndrome), in which people intentionally restrict their sleep in order to spend more time doing other things, like playing video games, working, or exercising.

Is Polyphasic Sleep Natural?

According to most scientists, humans are not naturally polyphasic, because we need longer sleep periods to move through all the necessary stages of sleep. But humans can sometimes use polyphasic sleep to adapt to extreme environments: For example, open-ocean yacht racers, astronauts in space missions and special operations military personnel follow polyphasic sleep regimens.

Unlike humans, rodents are naturally polyphasic, sleeping for multiple short periods instead of one or two longer periods.

Is Polyphasic Sleep Safe?

Polyphasic sleep enthusiasts tout the practice as a more efficient way to sleep. However, the effects of insufficient sleep syndrome show that chronic, intentional sleep restriction can have a steep downside.

Effects of ISS include excessive daytime fatigue, increased risk for vehicle and jobsite accidents, long-term endocrine and metabolic dysfunction, and decreased immune response.

Additional Resources