A lifetime sleep pattern looks like a U‑shaped curve, with 40 years as the lowest point, according to researchers at the Medical College of Georgia.
Our sleep efficiency, which basically means how much time we actually sleep, tends to decrease throughout our lives, but the researchers were surprised to find that the efficiency stabilized between the ages of 30 and 60.
For this study, researchers analyzed a representative sample of 200 million Americans: 11,279 participants aged 6 and over from the National Health and Nutrition Study. This is the first work that did not use sleep self-reports, but 24-hour monitoring data.
People think that children and teenagers sleep longer, and this has been proven true. And in middle age, people sleep less, and the results also objectively confirm this. In addition, sleep duration is increased for individuals aged 60 years and older.
In this more objective assessment of sleep parameters based on movement, the researchers again found that, in general, nighttime sleep decreases as we age, although they noticed that the U‑shape appears when sleep duration is significantly reduced from about 10 to 50 years old and gets a little longer after 50 years. Although the work reflected a pattern among residents of the United States, studies of large numbers of residents in Japan and France showed similar data.