The eight-hour rule is abolished: How much sleep do we need?;

If you’ve been feeling sleepy for several days and wishing you’d gotten a little more sleep, consider this: New research suggests that you may already be sleeping more than you need to, based on your age.

Specifically, according to new research from the University of Cambridge and Fudan University in Shanghai, the eight-hour workday, which many consider to be the ideal amount of sleep, is actually not suitable for people over the age of 38.

Based on an analysis of the sleep habits of 500,000 adults between the ages of 38 and 73, the ideal amount of sleep is closer to 7 hours.

The study participants were assessed for their cognitive abilities and asked to answer questions about their sleep habits and their physical and mental health. In fact, some also provided genetic information and other types of biometric data.

The study concludes that whether someone sleeps less or more than they should, has exactly the same consequences. In other words, although it is traditionally said that we should get eight hours of sleep, researchers show that sleeping eight hours (or more), as well as sleeping less than seven hours, has a negative effect on the body as we age. For example, over time, getting the wrong amount of sleep can lead to mental health problems and «poorer cognitive performance.».

A Date with Sleep

The study also concludes that consistency is key to getting a good night’s sleep. In other words, if you sleep six hours one day and nine the next, you’ll still feel groggy and tired. According to the researchers, if deep sleep is interrupted during the night, you may experience that morning «fog,» since the brain doesn’t have enough time to clear out toxins.

It also appears that getting the right amount of sleep has benefits for overall well-being, as well as for memory. The hippocampus, which functions as the «center» of memories, is affected by a lack of sleep or excessive sleep. Finally, among the most important findings of the study is the fact that adequate sleep reduces probability of disease occurrence.

Professor Barbara Sahakian of the University of Cambridge, one of the study’s authors, told the British newspaper *The Telegraph*: «Getting a good night’s sleep is important at all stages of life, but especially as we get older. Identifying ways to improve sleep for older adults can be fundamental to maintaining good mental health and well-being and preventing a decline in cognitive function, especially in patients with psychiatric disorders and dementia.».