Increased exercise in midlife may be linked to better brain health in later life, new research suggests.

According to the study, greater amounts of moderate-to-vigorous intensity physical activity like walking briskly, running and biking in middle age through later life may have a protective effect on the brain.

More physical activity during these phases of life is associated with less brain damage 25 years later, researchers found.

Priya Palta at Columbia University Irving Medical Centre in New York City said: “Our study suggests that getting at least an hour and 15 minutes of moderate-to-vigorous intensity physical activity a week or more during midlife may be important throughout your lifetime for promoting brain health and preserving the actual structure of your brain.

“In particular, engaging in more than two and a half hours of physical activity per week in middle age was associated with fewer signs of brain disease.”

The study involved 1,604 people with an average age of 53 who attended five physical examinations over 25 years.

Participants rated their weekly activity levels once at the start and again at two additional times.

Each person reported the amount of time they engaged in moderate-to-vigorous intensity physical activity, which researchers classified as none, low, middle or high.

Researchers then used brain scans to measure participants’ grey and white brain matter and lesions, or areas of injury or disease in the brain, at the end of the study.

After adjusting for demographics and lifestyle factors, people who reported no moderate-to-vigorous intensity physical activity in midlife were 47% more likely to develop small areas of brain damage than people who reported high levels of moderate-to-vigorous intensity physical activity.

Researchers used brain scans to measure the amount of damage to the brain’s white matter.

Dr Palta said: “Our results show that staying active during midlife may have real brain benefits.

“In particular, consistently high levels of midlife moderate-to-vigorous intensity physical activity were associated with fewer brain lesions in later life.”

But the study authors note that a limitation of the study is that it relied on participants reporting their own physical activity, which could be inaccurate.

Also researchers did not include physical activity other than leisure time activity – such as work-related or incidental activity.

The study is published in Neurology.

Dr Sara Imarisio, head of research at Alzheimer’s Research UK, said: “This research adds to a growing body of evidence suggesting exercise as an important way we can look after our brain health.”

She added: “Just a third of people think it’s possible to reduce their risk of developing dementia, compared to 77% who believe they can reduce their risk of heart disease.

“While there is no sure-fire risk way to prevent dementia, our brains don’t operate in isolation from the rest of our bodies and a good rule of thumb for everyone is that what is good for your heart is also good for your brain.

“The best current evidence suggests that as well as staying physically and mentally active, eating a healthy balanced diet, not smoking, drinking only within the recommended limits and keeping weight, cholesterol and blood pressure in check are all good ways to support a healthy brain as we age.”