On one particular night, I decided to flip on the lights and do something more productive for an hour before sleep finally came back my way. Strangely enough, I found that I was way more productive at 2 a.m. than I normally would be at 2 p.m. I thought it was pretty weird until my late-night scrolling taught me something interesting: hundreds of years ago, people would go to sleep, wake up and do various things, and then go back to sleep until morning.

What is segmented sleep?

Segmented sleep is a sleep pattern where a person breaks their sleep schedule into two or more segments, remaining awake in between those segments. When individuals sleep twice per day, this is known as biphasic sleeping; when people sleep in multiple segments per day, this is known as polyphasic sleeping. This practice of sleeping in shifts was considered normal centuries ago because people’s sleep schedules were not determined by a set bedtime, but instead by what they needed to get done. RELATED: If You Only Need 5 Hours Of Sleep, It Might Be In Your Genes (According To New Research) In most societies today, monophasic sleep, which is sleeping all the way through the night, is considered to be the norm. However, biphasic sleep schedules, a sleep schedule with two segments, still occur naturally in some and are even promoted in certain cultures. A biphasic sleep schedule may not look the same way it did in the past. Today, a biphasic sleep schedule can involve sleeping for six hours at night and taking a quick cat nap in the middle of the day.

What is the history of segmented sleeping?

Sleeping in two shifts has actually occurred for centuries. Historians and anthropologists have found numerous accounts of segmented sleep in diaries, court records, literature, medical books, and art. In 2001, historian Roger Ekirch published a paper that was drawn from 16 years’ worth of research, giving historical evidence that humans used to sleep in two distinct shifts. In the Middle Ages through the late 1500s, falling asleep a few hours after dusk was common practice. People would often sleep for three or four hours before experiencing a waking period of one or two hours, and then finally a second shift of sleep until the morning. During this one-to-two hour waking period, people would get up, smoke tobacco, read, write, pray, and some would even go pay their neighbors a late-night visit. Many prayer manuals from the late 16th century show there were specific prayers for the hours in between the two sleeps. Social visits and prayers were not the only popular activities for this time of night, though. A doctor’s manual from France, dated from the 16th century, advised couples that the best time to conceive was during this waking period. The manual explained that couples would “do it better” and “have more enjoyment” because they were not as tired from a hard day of work. Throughout the late 17th century, this practice of sleeping in two shifts slowly began to disappear. By the end of the 19th century and into the 1920s, it had vanished from society altogether. The emergence of artificial light, like streetlights and domestic lighting, and coffee houses that stayed open all night, were to blame for the change. While split sleeping was no longer a practice in society, people still didn’t always get a full night’s rest. Around the time that sleeping in shifts disappeared from historical accounts, particularly during the Industrial Revolution, insomnia began to appear in literature. Society shifted its view of waking up in the middle of the night from being normal to being considered a problem. The pressure to now sleep through the night may have exacerbated the problem, causing anxiety in those who would typically wake up for an hour. RELATED: People Who Wake Up Early Are Smarter, Healthier & More Productive

Where is segmented sleep still common?

Certain cultures promote a nap in the middle of the day, especially after lunch time. In the Mediterranean, Latin America, and Spain, taking a quick nap, or siesta, six hours after waking is common practice. The siesta normally occurs between 2 p.m. and 5 p.m., depending on the location. In some Spanish towns, businesses will close for several hours while children are brought inside from playing in order to keep the streets quiet. Siestas allow people to relax and rest during the hottest part of the day. Our body-clock naturally wants to rest at this hour due to reduced alertness in the early afternoon, also referred to as the “post-lunch dip.”

Is segmented sleep healthy?

According to registered occupational therapist Judith Pinto, “It’s important to remember that the neurobiological process that is sleep doesn’t happen in a single eight-hour stint. We have sleep cycles or circadian rhythms — periods of deep sleep followed by near wakeful periods. Waking up several times is perfectly natural.” However, Pinto also pointed out that sleeping in two shifts may pose some challenges in this day and age. “Having to be ‘on-site’ (at the office or school), alert and productive between nine in the morning until five in the evening isn’t a ‘natural’ expectation — it’s a man-made construct,” Pinto says. Today, we rarely go to sleep and wake up with the sun, so waking up in the middle of the night and sleeping in the next morning is not always attainable. Even taking a nap in the middle of the day after sleeping in two shifts is off the table with the average nine-to-five work day. Another challenge is the idea that sleeping for eight consecutive hours at night is the only healthy option. “The false belief (and anxiety that comes with it) that if we’re not completely asleep for a solid eight hours between 10 p.m. and 6 a.m., we’re doing it wrong and aren’t getting enough sleep, which inevitably leads us to expect worse performance the next day,” Pinto states. “And, of course, the only reason we need to fit all our sleep in at those times is so that we can function between 9 a.m. and 5 p.m. It’s a vicious cycle!” Although sleeping in shifts may come with some challenges, sleeping with the schedule of our natural biorhythms is more beneficial than eight consecutive hours of sleep. “Anytime we work with our natural biorhythms — without external pressures to push through or ignore our body’s needs — the better. We’re more likely to be at our personal best in terms of health and wellbeing and function at our best in our work and in our relationships,” she adds. While sleeping in shifts may not be attainable in society today, it definitely has benefits to our health and wellbeing. RELATED: What It Means About Your Mental And Physical Health If You Wake Up At The Same Time Every Night Livvie Brault is a writer who covers trending news and entertainment, relationships, and lifestyle topics.