New research reveals: People who exercise and stay up late may have been "ineffectively exercising"

Expert interviewed: Gao Wei, chief physician of the Department of Neurology, Peking University Shougang Hospital

Exercise is a good medicine, which can prevent chronic diseases, prolong life, and prevent dementia. However, a new study published in The Lancet Health and Longevity shows that if you sleep less than 6 hours a night, even if you exercise, your cognitive ability will decline at the same rate as sedentary people.

This is a full cohort study of the British population, including data from 8,958 people (50 years and above) in the UK Longitudinal Study of Ageing database. Based on the average sleep duration of participants per night on weekdays, scientists from University College London divided them into three groups: short sleep group (less than 6 hours), optimal sleep group (6-8 hours) and long sleep group (more than 8 hours). Over a period of 10 years, the researchers assessed their cognitive abilities through memory and verbal fluency tests.

After analysis, the researchers found that those who were more physically active but had shorter sleep time (less than 6 hours) had a faster decline in overall cognitive ability; for those who slept 6 to 8 hours a night (the best sleep time), regular exercise was associated with high cognitive function. However, for the elderly over 70 years old, even with less sleep, exercise can still help keep the brain healthy.

The lead author of the study, Mikaela Bloomberg of the Institute of Epidemiology and Healthcare Research at University College London, pointed out that adequate sleep is the basis for exercise to promote cognitive improvement. Regular exercise cannot offset the long-term impact of lack of sleep on cognitive health, which needs to be taken seriously.

Gao Wei, chief physician of the Department of Neurology at Peking University Shougang Hospital, told the Global Times Health Client: "This study highlights the importance of sleep and exercise to brain function, especially in preventing cognitive decline. Combining the two is more beneficial to brain health."

After a person falls asleep, the activity of nerve cells in the brain changes, and generation and reconstruction begin; at the same time, sleep can also help remove toxins from the brain, deliver nutrients, and promote the generation of brain cells. After this process, our brain can get rid of chaos and have stronger cognitive abilities. "If you only lack sleep occasionally, you can recover with proper sleep. But if you don't get enough sleep for a long time, it will be difficult to reverse the brain damage that has occurred, whether it is exercise or medical means." Gao Wei said that from the "U"-shaped curve of the relationship between sleep duration and the risk of cognitive impairment, it can be seen that sleeping 6 to 8 hours a night is the best sleep duration, and too much or too little is not good for brain health.

At present, the World Health Organization (WHO) has identified physical activity as a way to maintain cognitive function. Gao Wei explained the reasons. First, exercise can relieve brain tension, protect neurons to a certain extent, and effectively slow down brain aging. Second, during exercise, blood circulation speeds up, which can enable the brain to obtain more nutrients and oxygen, helping to improve people's memory and thinking ability. Third, proper exercise can reduce anxiety to a certain extent and maintain people's psychological or mental health.

However, most people currently face the problem of insufficient exercise, especially "office workers" who are busy and stressed at work. They have no time to exercise and often stay up late and sleep late, which is a double hazard to health. Therefore, Gao Wei suggested that you might as well use fragmented time to exercise more, such as taking a walk after lunch, stretching during work breaks, and riding a bike or walking the last kilometer home from get off work. Over time, good exercise habits will be formed. At the same time, try not to stay up late and maintain 6 to 8 hours of sleep a day. "Good sleep + insisting on exercise can ensure brain health and prevent cognitive function from declining."

(Global Times Health Client reporter Guo Shiying)