Back in September, 32-year-old physicist Sam Novario’s quarantine-induced sleep schedule grew so chaotic that it finally split into two equal parts — every day for roughly six weeks, he would sleep from 11 a.m. to 2 p.m., and then again from 11 p.m. to 2 a.m. Novario says it was the best sleep he’s ever gotten, which is very much in line with the contents of the oft-viral 2018 article, “Humans Used to Sleep in Two Shifts, and Maybe We Should Do It Again,” that claims an evolutionary basis for sleeping in such a manner.
That the article has gone viral so often over the last couple of years makes sense. As it points out, “a third of the population have trouble sleeping,” and that’s not counting how much the pandemic has messed with everyone’s sleep schedule. If such a huge chunk of the population is sleep deprived, maybe we should consider returning to our (allegedly) more natural sleep schedules.
According to sleep expert Christine Hansen, the article isn’t totally wrong either. “This is called biphasic sleep, and it’s based on the fact that people used to go to sleep when it got dark and woke up again when it got light,” she explains. “This meant they had a lot of time, and so, they’d wake up in the middle of the night to do something like meditate or pray.” Then they’d go back to sleep for a few hours, and get up again when they had more physically-taxing work to do.
At the most basic level, nothing leads to good sleep like consistency. “Each of us is equipped with our own internal 24-hour body clock known as our circadian rhythm; it tells us when to rest and when to be alert, but it craves consistency,” says Bill Fish, a certified sleep science coach and managing editor of SleepFoundation.org. “Each person needs between seven and nine hours of quality sleep on a nightly basis, and it takes discipline to adhere to this schedule.”
Sleeping in two shifts works, then, in the sense that people used to adhere to their schedules with greater discipline. But in today’s world, both Fish and Hansen agree that it’s just not possible. “Sleeping in two shifts isn’t ideal,” Fish tells me. “If it were, far more people would be doing it. The approach might work for shift workers whose work hours are often changing, or if someone has a substantial amount of sleep issues and nothing else seems to work. But I’d go through a long checklist before I recommended a split sleep schedule for anyone.”
Even if it did jibe with someone’s work hours or improve the overall quality of their sleep, there’s a good chance they’d be sacrificing other human needs along the way. After all, as Hansen points out, for most people, sleeping in two shifts would “likely lead to social isolation,” which leads to depression, which given the state of the world, probably is to be avoided.
So while sleeping in two shifts is certainly what humans used to do, it’s incorrect to suggest people today would be better off doing the same. Along those lines, here’s what happened to Novario. “Whenever there was a real thing I had to deal with outside of my quarantine apartment fantasy, it threw a wrench into the system,” he says. For example, after three weeks of consistent two-shift sleeping, he joined a few friends for a Saturday night Zoom call. “I stayed up past midnight with them, then slept until 11 a.m,” he explains. “For normal people, this is just sleeping in, and it’d be easy to fix. But for me, after just one weekend, my sleep schedule was completely ruined.”
Faced with the choice of slowly working back to two shifts or sleeping through the night and being up for work in the morning, he chose the latter. Still, maybe it’s his sleep-deprived brain or maybe this is what happens when you’re the guinea pig to your own scientist, but Novario can’t help but want to run another experiment.
“I guess I could try sleeping from 5 a.m. to 9 a.m. and 5 p.m. to 9 p.m., which would theoretically have me awake for most of the work day,” he concludes. “So maybe if I do it again, I’ll try it that way. I’ll miss out on fast-food breakfast, but at least my family won’t freak out after I’ve slept through multiple phone calls.”