The year is 1600. The sun has just set and you’re tucked up on your canvas sack on the floor.
But shut-eye in medieval times had a twist: instead of the eight-hours-a-night routine we’re familiar with, going to bed in the olden days meant getting up around midnight for a chunk of time known as “the watch” before hitting the hay again until morning.
Maybe you get on with some chores. Maybe ponder or pray for a couple hours. Maybe you pen a letter by candlelight. Maybe you even had sex. Then, back to bed until sunrise.
Unlike our modern goal of one uninterrupted stretch of slumber, in pre-industrial Europe, sleeping in these two distinct stretches—called biphasic sleep, or sleeping in two phases—was common.
This past summer, inspired by her medieval studies, Anna Fox, a graduate student at North Carolina State University, decided to experiment with waking between 1:30 a.m. and 3:30 a.m. In this time, she read books, wrote letters, journalled and worked creatively, documenting her experiment on social media. Thousands tuned in.
“It was kinda just curiosity to see what would happen,” Fox tells Fast Company. “Part of me was secretly hoping I was built for a medieval lifestyle and it would cure my chronic fatigue.”
While that didn’t happen, what Fox didn’t expect was how drastically this time for contemplation would affect her creativity. “I was writing better poetry than I’ve ever written in my life,” she says. Her rules for this experiment: No overhead lighting, no phone, and no to-do list items.
“I knew if I started doing that,” she says, then the experiment would’ve become about “how much I can multitask and get done and crank out during those hours. And that wasn’t the intention,” she says. Instead, she was able to lean into the peacefulness of those midnight hours.
“It was hard to wake myself up in the middle of the night each time. But once I was awake, the actual time during the night was really lovely.”
Fox isn’t the only one who has experimented with unusual sleep patterns. Biphasic sleepers throughout history include the likes of Charles Dickens, who famously chronicled his “night walks.” Inventor Thomas Edison also championed polyphasic sleep and claimed that he never slept more than four hours a night.
In the 1980s, historian Roger Ekirch first stumbled across this idea of “first sleep” and “second sleep.” Nowadays, most of us sleep monophasically—in a single stretch. Still, many experience waking up at 3 a.m., completely alert and unable to fall back asleep until a few hours pass, mentally counting down the hours until your alarm.
Does this mean we should learn from our ancestors, and spend this time tackling chores or working on creative projects—the way our modern-day, productivity-maxxing selves might be inclined to do?
Modern work changed everything
There are reasons why most of us don’t sleep like this anymore.
During the Industrial Revolution, gas lamps were installed on the streets and artificial lighting was adopted in homes, allowing people to extend their waking hours beyond nightfall. This compressed their sleep into a single stretch, while medieval sleepers’ circadian rhythms relied more on going to sleep after night fell. This may have meant going to bed earlier and then waking up in the middle of the night.
In the early 1990s, psychiatrist Thomas Wehr conducted an experiment in which a group of participants was deprived of artificial light at night for several weeks. By the fourth week, they had naturally settled into a segmented sleep cycle. Some communities without electricity still show segmented sleep patterns: a 2017 study found that was the case with a community in Madagascar.
“Thomas Edison—when he invented that thing called the light bulb—screwed it up for everybody, because all of a sudden, you could work at night,” says Dr. Michael Breus, clinical psychologist and chief sleep officer at Orion, a sleep tech startup.
Work culture also shifted during this period: The Industrial Revolution gave rise to rigid schedules based on factory demands, which led to the modern 40-hour work week. The idea of overtime also emerged during this period.
“The concept of paying people more for working at non-desirable times also became something that was highly paid and highly sought after,” says Dr. Breus. The industrial economy shifted our relationship to work and productivity, and with it, left little room for midnight pondering or prayers.
However, segmented sleep did not entirely disappear. “You’d be surprised how many people actually participate in biphasic sleep currently,” says Dr. Breus. In fact, he says those who regularly take naps during the day would be described as biphasic sleepers. And every few years, the idea of segmented sleep reemerges as a potential solution for middle-of-the-night insomnia.
And yet? “The [American Academy of Sleep Medicine] basically says that there’s no substantial cognitive or health benefit of polyphasic sleep, or biphasic sleep,” says Alen Juginović, sleep researcher and postdoctoral fellow at Harvard Medical School.
‘Modern sleep is short sleep’
Even though our forebears didn’t have blue light-spraying smartphones or after-hours emails to keep them awake, it doesn’t mean their way of sleeping was necessarily better.
A 2021 review published in the journal Sleep Health found no benefits to polyphasic sleep. (“Polyphasic” means sleeping in many phases in a 24-hour period.) It was actually associated with adverse physical health, mental health, and performance outcomes.
“We know from these large studies that, generally, a low amount of sleep is really harmful for long-term health outcomes,” says Juginović. “Getting eight hours of sleep across multiple periods is likely better than getting only five hours, because total sleep duration is extremely important for health. However, regularly dividing sleep into several shorter periods may disrupt our circadian rhythm and natural sleep architecture.”
Over time, the amount of time we spend asleep has only gotten shorter as our lives have gotten busier.
“The American Academy recommends a minimum of seven hours for adults,” says Juginović. “But because of work culture and lifestyle factors, modern sleep, sadly, is generally short sleep.”
Listen to your own body
Polyphasic sleep isn’t necessarily good, but neither are the myriad ways modern-day sleep gets disrupted and shortened.
Instead of experimenting with medieval sleep regimens, anyone looking to improve their sleep and productivity during waking hours is best off sticking to the basics.
“Get seven to nine hours of sleep if you can. If you can do it at a consistent time period,” says Dr. Breus. “Generally speaking, the work that you perform in the middle of the night isn’t nearly the quality of what you would do on a well-slept brain.”
But at the end of the day—literally—listen to your body, as everyone has slightly different natural sleep tendencies.
As for Fox, although she doesn’t have plans to continue her experiment long-term, she liked the medieval sleep treatment because it was a time she wasn’t distracted by her phone, other people or the demands of the day.
“I think part of it was the solitude,” she says. “It feels like those hours just belong to you.”
Juginović concedes that fewer distractions may allow for more creative thinking and focus. “Research also suggests that the transition between wakefulness and sleep, known as the hypnagogic state, can promote creative insights and unusual associations between ideas,” he says. “However, this does not mean that staying awake at night or disrupting sleep improves creativity overall.”
If inspiration strikes at 3 a.m., or you do your best work when the rest of the world is asleep, a medieval sleep routine might work for you. But, Dr. Breus caveats: “I wouldn’t set an alarm to wake myself up.”
“I would definitely not wake up at two a.m. to do some emails,” he adds.
