Today, many people – including doctors, still consider waking up in the middle of the night and not being able to take a nap as a disease, calling it insomnia. All who fall into this situation will try to force themselves to sleep, close their eyes and not forget to torment themselves that they have had a bad sleep.
But have you ever thought the opposite is true or not? In fact, humans have such a naturally segmented sleep pattern, they wake up in the middle of the night and then go back to sleep and stay healthy.
How did people sleep in the pre-industrial era?
Throughout human history, there has been a great deal of sleep literature, from medical documents, court records, personal diaries to tribal African records. or South America.
Anthropologists found evidence that during pre-industrial Europe in Europe, fractional sleep was considered the norm. Book “At Day’s Close: Night in Times Past“by historian A. Roger Ekirch describes how households at that time took a nap from the moment the sun began to set. They then wake up and work for one to two hours. , before going back to bed and sleeping until sunrise.
During this mid-waking period, people will often relax, meditate on their dreams or have sex. Some will participate in activities such as sewing, cutting wood or reading books in the light of the moon or oil lamps.
However, when Ekirch re-started to re-examine ancient texts, he found this fractional sleep pattern disappear at the end of the 17th century. High-class people living in Nordic society are said to have disrupted fecal sleep. the first part, instead, they slept from night to morning. Over the next 200 years or so, this sleep pattern began to spread to the rest of Western society.
Interestingly, around the end of the 19th century, when segmented sleep disappeared, records of insomnia began to appear. Scientists therefore suspect that insomnia is actually a remnant of a natural and standard sleep paradigm. Modern society may be exerting an unnecessary pressure on everyone to sleep that we need to sleep without interruption.
One form of biphasic sleep that is still common in today’s society is napping in the early afternoon. The circadian clock inside our bodies often falters after lunch until 15 o’clock, a phenomenon known roughly as “abdominal stretch, eye sagging”.
In the early 1990s, psychiatrist Thomas Wehr ran an experiment in which he exposed a group of people to a short cycle of light during the day – meaning they were left in the dark for 14 hours. per day instead of the usual 8 hours.
Experiment took place for a long time within 3 weeks with no results. But by the fourth week, the segmented sleep pattern had begun to emerge. Volunteers participating in this study started napping for four hours, after which they woke up 1-3 hours before falling back to sleep for another four hours.
Thomas Wehr’s experiment shows that fractional sleep is a natural process with a biological basis.
Advantages and disadvantages
In today’s society, segmented sleep does not seem acceptable. Many medical guidelines and sleep recommendations agree that people should sleep 7-9 hours a night, and it’s best not to wake up once in between. Such a sleep schedule may not be appropriate for our circadian rhythms, however, as it doesn’t seem to sync with the outside 24-hour morning / evening cycle.
A single 8-hour nap will induce sleep during the other 16 hours. As a result, this sleep schedule sometimes accumulates feelings of lethargy and makes you ineffective.
Conversely, a segmented sleep schedule can be more flexible and allow you to have 2 periods of increased activity, creativity and alertness during the day. Nowadays, there is also a lot of evidence that naps have many important benefits for memory and learning, helping us increase alertness and improve our mood.
Some people believe that sleep disorders, such as insomnia and mid-night waking, are rooted in the body’s natural preference for fractional sleep. So a broken sleep schedule may be a more natural rhythm for some people.
But to be able to successfully maintain a segmented sleep schedule, you must choose the right time – that is, you must start sleeping as soon as there is a strong need for sleep and during a time the circadian clock is running low. This will allow you to fall asleep quickly and sustain it for the required time.
The fractional sleep schedule has also recently been introduced as a potential alternative for workers who have to work night shift continuously. Before that, night shift work caused a lot of health problems because of the difference in circadian rhythm it caused.
Workers often stay up for 8-12 hours continuously complaining of fatigue and reduced productivity. Research shows they are also at increased risk for chronic diseases such as obesity, type 2 diabetes and cardiovascular disease.
As a result, some companies have begun adopting a flexible work schedule that allows workers to sleep between their work shifts or divide them into 6-hour shifts, 6-hour breaks, 4-hour 8-hour shifts and 8-hour shifts 8 hour breaks to reduce their continuous stay awake.
The work shifts will be shorter, alternating with rest time, but in return workers will have to work more shifts. Despite this, their performance and health benefits were well documented. Some recent studies have found that fractional sleep offers benefits equivalent to a continuous, uninterrupted sleep, as long as you can get 7-8 hours of sleep on a 24-hour cycle.
So while we know many of us expect a constant night’s sleep, this may not be consistent with everyone’s body clock or work schedule.
In fact, waking up in the middle of the night and doing something around this time may better fit the fractional overlay pattern of our ancestors who lived in the pre-industrial era. For some people, this sleep pattern can still work for them in today’s modern society.