Sleep Stage Repartitioning

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Sleep repartitioning is a method practiced by polyphasic sleepers that’s designed to shake up your typical sleep cycle. Instead of sleeping through the night and cycling through each sleep stage, polyphasic sleep involves distributing sleep across multiple shorter periods throughout the day or night. 

According to those who swear by this alternative lifestyle, over time, you can train your body to rearrange sleep stages so you can make the most of your shut-eye.

Science has yet to validate the claims made by this niche group, but the idea of sleep repartitioning is an intriguing one. So let’s take a closer look at how it may work and whether or not to give it a try.

Is Sleep Stage Repartitioning Safe?

The National Sleep Foundation recommends that healthy adults get at least 7 hours of sleep. Most polyphasic sleep schedules, though, only allow for about 2 to 6 hours of sleep. That means polyphasic sleep often results in sleep deprivation. 

Sleep deprivation is linked to some serious health concerns. Research suggests that it could lead to worse performance, more frequent accidents, and even put you at higher risk of heart attack or stroke.

This is important to keep in mind when weighing the pros and cons of trying sleep repartitioning. 

The Theory Behind Sleep Stage Reparititoning

During a typical night of monophasic sleep, your body will continuously cycle through four to five sleep stages until you wake up. 

You’ll start out in non-REM (NREM) sleep. These sleep stages are associated with functions like memory building and muscle recovery. Rapid eye movement (REM) sleep is when dreams occur and may help you process emotions. It involves lots of brain activity so it isn’t considered deep, restful sleep. Each sleep cycle takes about 90 minutes, and the longer you sleep, the longer your stretches of REM sleep will be.

Polyphasic sleep aims to maximize the time spent in REM sleep rather than the hours spent sleeping in general. By sleeping in several shorter blocks of time, the idea is to use sleep deprivation to drive your brain into REM sleep more quickly. There’s even some evidence that extreme sleep deprivation can do just that.

But is this a good idea?

While every sleep stage is important, deep non-REM sleep (also called N3) is when your brain conducts some of its most important unconscious work, like:

  • Building bones
  • Building muscles
  • Tissue repair and regeneration
  • Strengthening your immune system
  • Memory processing

N3 is also believed to be the most “restful and restorative phase of sleep.” If you’re reducing the amount of time you sleep, and you’re actively trying to increase REM sleep, you’re also reducing the amount of time you spend in deep sleep.

Sleep Repartitioning During Core Sleep

In the polyphasic world, “core sleep” is the term used to describe the longest sleep block in your schedule. Depending on which pattern you follow (and there are many), your core sleep could be anywhere from 2 to 6 hours.

As your body adjusts to this new schedule, the goal of repartitioning is for your sleep stages to adjust as well. At first, your core sleep will mimic a traditional monophasic sleep cycle. 

That means you’ll experience light NREM sleep, then deep NREM sleep, followed by increasing lengths of REM sleep. You’ll cycle through the phases for as long as your sleep block allows.

If you wake up during the deep sleep phase, you’ll likely have “sleep inertia” which can make you feel groggy and disoriented

Over time, polyphasic sleepers claim that your body will rearrange the phases, so deep sleep happens first, usually during the initial sleep cycle. REM may also appear much earlier and dominate the remaining sleep cycles in your block. In theory, this would allow you to feel well-rested and energized while getting less sleep—though no scientific study has proven this to be the case.

Sleep Repartitioning During Naps

Napping is a huge part of polyphasic sleep. In fact, some sleepers only take naps and don’t have a dedicated “core sleep” block at all. No matter which schedule you follow, you’ll likely have at least one or two dedicated nap times during the day.

Of course, the nap stage is much shorter than the core sleep stage. So, initially, you probably won’t experience any REM sleep at all during naps. And you’ll only go through your deep sleep phase if you didn’t get the amount you needed during your core sleep.

After some consistent practice, your body supposedly should adapt and get you into the REM cycle much more quickly. Many polyphasic sleepers claim to have REM-filled naps every day, but again, all the evidence is anecdotal and has not been proven.

Differences in a Monophasic Schedule

There’s no need to repartition your sleep stages during a monophasic schedule because your body should naturally work its way through the stages during a single, uninterrupted sleep block. If you think you’re not getting enough deep or REM sleep, you should focus on improving your sleep hygiene rather than trying to hack your body’s internal clock.

Try creating an optimal sleep environment, going to bed at the same time every night, and starting a relaxing evening ritual to help you wind down before sleep. These simple changes should help you get the most out of your monophasic schedule—and you won’t have to worry about sleep repartitioning at all.


While sleep repartitioning is a controversial topic in the sleep world, many polyphasic sleepers believe it’s the key to getting the most out of their short snoozes. 

If you’re thinking about trying a polyphasic sleep schedule, talk with your doctor first. If they say it’s okay, be prepared for some trial and error. It may take your body some time to adjust to the new sleep pattern—if it’s able to adjust at all. 

Source List

Feriante J, et al. (2022). REM Rebound Effect. 

Here’s What Happens When You Don’t Get Enough Sleep (and How Much You Really Need a Night). (2022).

Hirshkowitz M, et al. (2015). The National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep Health.

Institute of Medicine (US) Committee on Sleep Medicine and Research. (2006). Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem.

Nikbakhtian, S, et al. (2021). Accelerometer-derived sleep onset timing and cardiovascular disease incidence: a UK Biobank cohort study.

Scarpelli, S., et al. (2019). The Functional Role of Dreaming in Emotional Processes.

Sleep Basics. (2021).

The Science of Sleep: Understanding What Happens When You Sleep. (2022).