Could A Bizarre Sleep Routine Practiced By Early Humans Be Key To A Good Night’s Rest?

Daylight savings ends on November 5: Sleep schedules be warned. Soon, and probably to your dismay, you’ll find yourself looking out the window at 4:30 p.m., wondering why it’s so dark, and your daily Zzz might take a turn for the worse.

But before humans invented daylight savings, there’s evidence our early ancestors slept according to waxing and waning daylight throughout the seasons. A 2015 paper published in the journal Current Biology, for instance, analyzed the sleep schedules of three pre-industrial civilizations in Tanzania, Namibia, and Bolivia and found that their habits looked very different from our tidy bedtime routines.

These three unrelated groups exhibited similar behaviors, but they were distinct from how modern humans sleep today. They appeared to follow what we now call polyphasic sleep schedules, where sleep is broken down into smaller chunks. For example, sleeping in three discrete shifts in a 24-hour period.

If it worked for our ancestors, should we try it too? Polyphasic sleep may seem like a good way to boost productivity. Here’s what you should know about the sleep practice and whether it's actually worth trying.

What is a polyphasic sleep schedule?

Most of us practice what’s called monophase sleeping. Our rest period is one large, extended chunk.

Biphasic sleeping, another method, is basically another way to say, “I like napping,” at least in modern times. A biphasic sleeper typically gets one long sleep period plus a shorter doze sometime during the day. This might look like the Western European siesta when shops close for the afternoon.

Polyphasic sleep schedules split our sleep time into at least three segments throughout a 24-hour period, and they can get quite weird and messy.

There are a few established polyphasic sleep practices, some with characteristic names:

• Triphasic: Three periods of sleep, one after dusk, one before dawn, and one during the day, amounting to 4 or 5 hours total.
• Everyman: Sleep 3 hours at night and then take three 20-minute naps throughout the day, totaling 4 hours of sleep.
• Ubermensch: This regimen calls for a 30-minute nap every 4 hours.
• Dymaxion: Originated by American architect R. Buckminster Fuller, this extreme sleep schedule comprises one 30-minute nap every 6 hours, adding up to 2 hours of sleep per day.

The purported magic of polyphasic sleep is that you harness the power of deep sleep, which usually occurs in the first part of a sleep cycle, so shortly after falling asleep.

“If you look at the standard sleep period, our sleep is typically deepest at the beginning of the night, and then it's getting more and more shallow,” Mathias Basner, professor of sleep psychiatry at the University of Pennsylvania’s Perelman School for Medicine, tells Inverse. The idea is that with polyphasic sleep, you hit the hay and immediately enter that deepest stage of sleep. “You're basically capitalizing on this deeper sleep at the beginning of the sleep period,” he says. “Basically, you're getting the biggest bang for your buck.”

Is polyphasic sleep good for you?

Running on little to no sleep might give someone a reputation for productivity, but sleep is actually quite productive in itself, Abhinav Singh, medical director of the Indiana Sleep Center, a medical review expert at the Sleep Foundation, and the author of the book Sleep to Heal wrote to Inverse.

Regular sleep cycles aid in bodily growth and repair, memory consolidation, metabolic regulation, immunity modulation, and maintenance of every cell and tissue. Insufficient sleep creates a great risk for a slew of health problems, including heart disease, dementia, and cancer.

With polyphasic sleeping, everything that 7 to 9 hours of sleep accomplishes gets truncated in short bursts of rest. “Polyphasic sleep more than likely disrupts this routine,” Singh says. “It is like letting a washing machine run half the cycle and then restarting in small bits later on.”

Basner adds that there’s an added layer of transitioning to and from sleep several times a day that most people don’t think about. Falling asleep and waking up are processes, not simple switches. In fact, the first stage of falling asleep is that penumbral state between waking and sleeping.

“The brain needs time to come online again to fire up all the systems,” Basner says. “It can take up to an hour or even longer, depending on which state you're awake from, to be fully alert again.” He refers to this post-wake period as sleep inertia when our body and mind transition from dormancy to activity.

“If you do this four or five times a day, you always have to transition into and out of sleep,” Basner says. “That just takes time. It also means that for 30 minutes or one hour after waking up, you're actually not performing at your best.” Essentially, what you may gain in available time, you may lose in cognitive function.

A 2021 review of literature on this practice published in the journal Sleep Health found that polyphasic sleep regimens are associated with many adverse physical and mental effects. The study authors found no benefits to polyphasic sleep.

Basner is frank in his medical opinion of polyphasic sleep. “I would say it makes no sense. I can't really see the advantages.”

So if you are looking to hack your sleep, establishing a proper sleep routine and making sure you are getting the proper seven to nine hours of sleep a night should more than do it.