Five hundred years ago there was little light available in the evening. People generally went to sleep around dusk. Researchers reviewed old books, documents and religious tracts. They discovered that people usually slept about four hours, woke up for 1 to 2 hours and went back to sleep for another four hours.
One study said, people got up, went to the bathroom, smoked, walked around and often prayed. There were special prayers for the hours between sleeps. A doctor’s manual said the best time to conceive was, “after the first sleep, when they enjoy it and do it better.”
It was known as first and second sleeps. It changed over time as people began to take control of the nighttime. Lighting played a big role. Activities took place later into the night. Eventually people had less time to sleep.
First and second sleeps were forgotten. By the middle of the 19th century, sleeping through the night became routine. One scientist said, “For most of evolution we slept a certain way. Waking up during the night is part of normal human physiology.”
Today, doctors say eight hours of continuous sleep is normal. New studies say it is more relaxing the next morning to sleep the way they did five hundred years ago.