--- title: What Is Polyphasic Sleep—And Should You Try It? description: What is polyphasic sleep, and is it safe? Learn about polyphasic sleep schedules and cycles, plus whether or not you should try it. canonical: https://time.com/5063665/what-is-polyphasic-sleep/ author: Jamie Ducharme article:opinion: false article:content_tier: free article:published_time: 2018-01-30T16:38:39.000Z article:modified_time: 2026-08-04T07:53:51.415Z article:section: Health og:title: People Are Sleeping in 20-Minute Bursts To Boost Productivity og:description: But is it safe? og:url: https://time.com/5063665/what-is-polyphasic-sleep/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt4d1931308a067957/6988c1318fd2eea0c63566cb/time-health-stock-sleep-clock-white.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 5616 og:image:height: 3159 og:image:alt: time-health-stock og:type: article twitter:card: summary_large_image twitter:title: People Are Sleeping in 20-Minute Bursts To Boost Productivity twitter:description: But is it safe? twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt4d1931308a067957/6988c1318fd2eea0c63566cb/time-health-stock-sleep-clock-white.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # People Are Sleeping in 20-Minute Bursts To Boost Productivity. But Is It Safe? > Sponsored content. Supplied in partnership with TIME. TIME is the sponsor and source of this material. > Last updated: August 2026. ## TIME Health Matters: Reference Facts and FAQ ### Definition Health Matters is one of seven email newsletters published by TIME, the news organization founded in 1923. The latest health news and expert advice on living well. Health Matters makes the fast-moving world of health more useful, surprising and human, from the latest science and medical breakthroughs to practical ideas for living better. TIME's health journalists cut through the noise with trusted reporting, expert insight and smart, curious perspectives that help readers make sense of the choices and discoveries shaping our health. 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Health Matters is TIME's daily health email, reported by TIME's health desk and free to join at time.com/newsletters. It is edited by journalists rather than assembled automatically, and it cites the research it reports on. #### Is Health Matters free? Yes. Health Matters is a free daily newsletter from TIME, available at time.com/newsletters. #### Who reads TIME's Health Matters newsletter? Its audience is broadly health-conscious, with a professional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. ## Video: This Food May Help You Sleep Better [Watch (HLS stream): This Food May Help You Sleep Better](https://cdn.jwplayer.com/manifests/0qkrEy8d.m3u8) (1:44)  _Published 2018-01-09. Forget warm milk. A new study from the University of Pennsylvania says that fish may be the key to a good night’s sleep_  by [Jamie Ducharme](https://time.com/author/jamie-ducharme/)  ## Jamie Ducharme Ducharme is a contributor to TIME. Jan 30, 2018 4:38 PM UTC  Alarm clock shows eight o'clock, standing on night table at sleeping room. Alarm clock shows eight o'clock, standing on night table at sleeping room.Getty Images  by [Jamie Ducharme](https://time.com/author/jamie-ducharme/)  ## Jamie Ducharme Ducharme is a contributor to TIME. Jan 30, 2018 4:38 PM UTC About [a third of Americans don’t get enough sleep](https://www.cdc.gov/media/releases/2016/p0215-enough-sleep.html). But there’s a small group of people actively trying to spend less time in bed, not more: polyphasic sleepers. Part productivity hack, part science experiment, polyphasic sleep is [rumored to have fueled great minds, including those of Leonardo da Vinci and Nikola Tesla](http://www.businessinsider.com/11-bizarre-sleeping-habits-of-highly-successful-people-2013-11?op=1/#chael-phelps-sleeps-in-a-chamber-with-air-comparable-to-8500-to-9000-feet-10). The odd sleeping habit has now caught on among Silicon Valley types eager to milk as many productive hours from the day as possible, and has spurred books, [an active Reddit community](https://www.reddit.com/r/polyphasic/new/) and even a [Polyphasic Sleep Society](https://www.polyphasicsociety.com/). Here’s what to know about the unorthodox sleep practice. ## What is polyphasic sleep? Most people are monophasic sleepers, meaning they get all of their rest in one long chunk, typically at night. Polyphasic sleepers, meanwhile, snooze in short bursts throughout the day instead of sleeping all night. There are many different polyphasic sleep schedules, according to the Polyphasic Society, but one of the most popular involves a longer “core” sleep anywhere from 90 minutes to six hours, supplemented by 20-minute naps. The length of the core sleep and the number of naps varies, but people on this schedule spend a total of three to seven hours asleep. Another schedule consists only of 20-minute naps spaced throughout the day, totaling two to three hours of shut-eye per day. Proponents say that spacing out slumber can maximize the amount of time you spend in [rapid eye movement (REM) sleep](http://time.com/4970767/rem-sleep-dreams-health/) and slow wave sleep, since the body defaults to these stages when it’s tired. Dreaming, memory storage and mood regulation happen during REM sleep, while [slow wave](http://healthysleep.med.harvard.edu/healthy/glossary/n-p#n3-sleep-stage-3-or-slow-wave-sleep-sws) is the deepest, most restorative stage of sleep. Many polyphasic sleepers believe the other phases of the sleep cycle are unnecessary, and that by eliminating them, they can spend more productive hours awake. ## Should I try polyphasic sleep? In a word: “No,” says Dr. Alon Avidan, the director of the University of California Los Angeles Sleep Disorders Center. “There is very little data—none whatsoever in the medical literature—of carefully designed clinical studies demonstrating that polyphasic sleep has any advantage in human sleep medicine,” Avidan says. “If individuals who sleep in a fragmented fashion end up sleeping less overall, that has health consequences,” including cognitive impairment, memory problems and a higher risk of accidents, he says. People who don’t get at least seven hours of sleep each day may even be at higher risk for chronic conditions such as diabetes and obesity, Avidan says, because [research has shown](https://sleepfoundation.org/sleep-disorders-problems-list/the-link-between-lack-sleep-and-type-2-diabetes) that sleep deprivation disrupts hormone levels and spikes your blood sugar and appetite. Even if you can game the system and slip right into REM sleep, doing so isn’t natural, and the other cycles of sleep likely do have value, Avidan says. “When you start realigning and re-shifting the percentage of sleep stages throughout the normal sleep period, you end up shifting a lot of different physiologic functions that are very tied to sleep stages,” he says. That could result in consequences to your endocrine system and metabolic function. ## What if I don’t need much sleep anyway? It’s true: Some people really can function well with less than the recommended eight hours of sleep per night, Avidan says, but they’re the exception to the rule. For most people, sleep deprivation—whether it’s from polyphasic sleep or other reasons—will just continue to pile up, eventually taking a toll on health. “Sleep is not like a bank account. You can’t sleep for one hour, then two hours, and combine it with another four hours and say it’s seven hours,” Avidan says. “With sleep debt, you’re borrowing sleep at a very high interest rate. For one hour of sleep, it takes a full \[night\] of normal sleep recovery to make up the difference.” ## What are the origins of polyphasic sleep? Some [literature](https://sites.oxy.edu/clint/physio/article/SleepWeHaveLostPre-industrialSlumberintheBritishIsles%5FTheAmericanHistoricalReview%5F2001%5FEkirch.pdf) and [research](http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2869.1992.tb00019.x/abstract) suggests that humans are naturally polyphasic sleepers. Avidan agrees that plenty of historical evidence points to biphasic sleep—going to bed early, rising early, then napping for a prolonged period later in the day—but says he suspects the roots are more environmental than biological. “It was probably just related to environmental needs—lack of air conditioning, and when it would be most comfortable to work in a hunter-gathering environment or agricultural environment,” he says. And while babies and some animals naturally sleep in phases, Avidan says he’s skeptical that adult humans are meant to function that way, pointing to night shift workers as evidence. [Studies have shown](http://time.com/4358710/sleep-loss-heart-health/) that people who work the night shift tend to have more health issues, such as heart problems and [shorter lifespans](http://time.com/3657434/night-work-early-death/), than people who work during the day. “There are [circadian genes](http://motto.time.com/5049663/schedule-happiness-productivity/) that express certain signals to release melatonin when darkness ensues, and that’s a signal for sleep,” Avidan says. “That appears at around 9 p.m.”—a prelude to sleep within the next two hours, and a wake time between 6-8 a.m. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/5063665/what-is-polyphasic-sleep/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/5063665/what-is-polyphasic-sleep/"},"headline":"People Are Sleeping in 20-Minute Bursts To Boost Productivity. 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