TL;DR

• A biphasic sleep cycle is when you sleep in two separate blocks at night separated by a period of wakefulness.
• Health professionals strongly recommend getting at least 7 hours of uninterrupted sleep per night.
• Many medieval people followed a biphasic sleep pattern, and some researchers believe it was common among hunter-gatherers.
• Research suggests that humans vary in their sleep patterns over the course of our lives.
• There are four distinct stages of sleep ranging from two stages of light sleep followed by deep sleep and REM sleep.

What’s the History of Biphasic Sleep Cycles?

Studies suggest biphasic sleeping was the norm before we had electric lights, and that our early ancestors had biphasic sleep patterns.

Ancient humans living in hunter-gatherer societies are believed to have been biphasic sleepers, possibly for protection in case of threats during the night.

Historical references to a “first sleep” and a “second sleep” are found in medieval literature describing people doing creative work or socializing in the middle of the night. The time between first and second sleep was said to be ideal for writing, reflection, and romance between couples.

Biphasic sleep patterns were common in the Middle Ages before the 8-hour workday turned our habits away from the pre-industrial customs of medieval biphasic sleepers.

This holds especially true in agricultural societies and warmer climates where people would sleep for a period during the day and for a shorter time at night.

What’s Driving the Biphasic Sleeping Trend?

Conventional wisdom tells us that we are meant to get about 8 hours of sleep each night, but what if you were told we humans used to do it differently? One often-cited 1992 study in the Journal of Sleep Research put 7 participants on a schedule where they had 10 hours of light and 14 hours of darkness.

Over the course of several weeks they began sleeping in two blocks during the dark hours, with 1-3 hours of wakefulness between sleeping periods. This, along with historical accounts, led to the theory that humans naturally sleep in two parts, called biphasic sleeping.

The practice of biphasic sleep has grown in popularity as people seek to improve their sleep quality. Life these days can get hectic, and modern humans have developed creative ways to deal with problems like insomnia.

If you’re curious about tracking your sleep cycles, an app like BetterSleep can help you understand your natural rhythm.

Tracking sleep with the BetterSleep App can help you identify sleep cycles and synchronize them with biphasic sleep or any sleeping pattern that works for you.

While biphasic sleep was once common, the rise of the 9-to-5 workday led to a shift toward monophasic sleep—one long, uninterrupted stretch of rest.

What’s the Difference Between Polyphasic and Biphasic Sleep?

Put simply, polyphasic sleep is anything more than one period while biphasic sleep is sleeping in two blocks separated by a wakeful period. Anything more than two periods of sleep is called polyphasic. Sleeping in one long and uninterrupted block as we do today is called monophasic sleep.

Some people take polyphasic sleep to an extreme, experimenting with schedules that may not be sustainable. Historic polyphasic sleepers include Buckminster Fuller, infamously known for adopting what’s called the ‘dymaxion’ sleep schedule, involving four 30-minute naps evenly spread out over a 24-hour period.

Some swear by similarly draconian sleep schedules like the ‘uberman’, where you only sleep for a couple of hours per day. Others engage in a series of “core” rests at night.

The less extreme practice of taking a siesta by resting in the afternoon is a form of polyphasic sleep practiced around the world.

Are Biphasic Sleep Schedules Healthy?

By now you’re probably asking yourself: ‘is biphasic sleep healthy ?’

Experts at the National Sleep Foundation strongly suggest getting at least 7 uninterrupted hours of sleep per night. If you’re experimenting with sleep patterns you could sleep for 7 hours and then take two 15-30 minute naps during the day, for example.

Sleep happens in four stages: two light sleep stages, deep sleep, and REM sleep. These cycles repeat every 90 minutes on average.

Many people think sleep quality stays the same all night, but it actually changes as we go through different sleep stages.

Humans vary in their sleep patterns over the course of our lives.

Newborn babies are natural biphasic sleepers, doing their sleeping in 3 or more periods over 24 hours. That changes when they reach the age of 5 or 6 years old and stop napping during the day.

Later on in life some elderly people who can’t sleep 8 hours at a time might begin to sleep in two blocks and transition to a biphasic sleeping pattern.

How Can You Benefit From Biphasic Sleep?

Potential benefits of biphasic sleep can include better productivity and feeling more alert during the day. Napping for 30 minutes or less has shown to improve alertness and reaction times.

Napping has also been shown to help with learning and memory retention, especially when the rest periods include REM sleep, allowing your brain to process the day twice in a 24-hour period.

Biphasic sleeping can be a more natural circadian rhythm for people who have trouble staying asleep all night. Biphasic sleepers have reported the ability to better recall dreams and sudden problem solving “aha ! ” moments when they wake up at night and during the period of wakefulness.

Any Risks Associated with Biphasic Sleeping?

When it comes to biphasic sleep schedules, it’s important to be aware of the potential risks. Tools like the BetterSleep App can help you avoid these common pitfalls.

Sleeping for too-short periods at a time can lead to sleep deprivation. Be aware that irregular sleep can disrupt your circadian rhythm, making it hard to get up on time.

Sleeping in irregular intervals might lead to sleep inertia, or feeling groggy when you wake up, especially if the crucial deep sleep and REM sleep stages are disrupted. Inconsistent sleep patterns can be associated with higher stress levels and cardiovascular problems.

Get Started With a Healthy Biphasic Sleep Schedule!

If you’re a biphasic sleeper or if you’re curious and want to try it out there are several things you can do to maximize benefits and minimize risks with a healthy biphasic sleep cycle.

You will want to start by making sure you have a comfortable sleeping environment where you can sleep uninterrupted, since every minute counts.

It’s important to stick to a consistent schedule, taking your first and second sleeps or daily naps at regular and consistent times to ensure your circadian rhythm stays in balance. The BetterSleep App makes it easy to organize your sleeping schedule.

BetterSleep helps you track sleep patterns, set a consistent schedule, and relax with soothing sounds, meditations, and bedtime stories. Try it tonight!