Exercising regularly can reduce the risk of cardiovascular disease by as much as a quarter, a new study has revealed. Researchers discovered that exercising helped to reduce stress-related brain activity associated with the development of cardiovascular diseases.

The study of more than 50,000 people found that those who met workout recommendations of 150 minutes a week had a 23 per cent lower risk of developing cardiovascular disease than those not meeting these recommendations. Those with stress-related conditions such as depression exhibited the most benefits from exercising.

Experts say the study, published in the Journal of the American College of Cardiology, demonstrates how physical activity can lead to beneficial effects in the brain. To assess the mechanisms underlying the psychological and cardiovascular disease benefits of physical activity, the researchers analysed the medical records and other information of 50,359 participants from the Mass General Brigham Biobank who completed a physical activity survey.

A subset of 774 participants underwent brain imaging tests and had measurements of stress-related brain activity taken. The study, led by investigators at Massachusetts General Hospital (MGH), found that over an average follow-up of ten years, 12.9 per cent of participants developed cardiovascular disease.

Those who met physical activity recommendations were seen to have a risk of developing cardiovascular disease nearly a quarter (23 per cent) lower than those not meeting the same recommendations. Participants with higher levels of physical activity also tended to have lower stress-related brain activity.

The researchers found that reductions in stress-associated brain activity were notably driven by gains in function in the prefrontal cortex - a part of the brain involved in executive functions such as decision-making and impulse control. They found the cardiovascular benefit of exercise was also twice as strong in participants who would be expected to have higher stress-related brain activity, such as those with pre-existing depression.

Dr Ahmed Tawakol, an investigator and cardiologist at the Cardiovascular Imaging Research Center at MGH and senior author of the study, explained: "Physical activity was roughly twice as effective in lowering cardiovascular disease risk among those with depression.

"Effects on the brain’s stress-related activity may explain this novel observation. Prospective studies are needed to identify potential mediators and to prove causality.

"In the meantime, clinicians could convey to patients that physical activity may have important brain effects, which may impart greater cardiovascular benefits among individuals with stress-related syndromes such as depression.”