A new study has found that exercising regularly can help slow down the ageing of the heart and main arteries if done at least four times a week.

Exercising four times each week for about 30 minutes could keep the heart and main arteries youthful, according to the latest research from the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital and the University of Texas Southwestern Medical Center.

The study found that shorter workouts can still be beneficial by minimizing the stiffening of middle-sized arteries, which supply blood to the head and neck.

The researchers examined the records of 102 people over 60-years-old. The participants were divided into four categories based on the amount of exercise they had done. Those who exercised fewer than twice a week were put into the sedentary group, while those who exercised two or three times each week were classified as casual exercisers. People who exercised four to five times were grouped as committed exercisers, while those who do it six to seven times were considered master athletes.

The research showed that the people who exercised two to three times each week had healthier middle-sized arteries, while those who exercised four or more times had healthier larger arteries, which supply blood to the chest and abdomen.

"This work is really exciting because it enables us to develop exercise programmes to keep the heart youthful and even turn back time on older hearts and blood vessels," said lead author Dr. Benjamin Levine, as reported by Daily Mail.

Factors such as diet, social background and education were not considered for the new research, which was published in the Journal of Psychology.

"Previous work by our group has shown that waiting until 70 is too late to reverse a heart's ageing, as it is difficult to change cardiovascular structure even with a year of training," Levine, co-founder of the Institute for Exercise and Environmental Medicine, was quoted by the Daily Mail as saying.

"Our current work is focusing on two years of training in middle aged men and women, with and without risk factors for heart diseases, to see if we can reverse the ageing of a heart and blood vessels by using the right amount of exercise at the right time," he added.

A separate study conducted by researchers at the Johns Hopkins University in Baltimore earlier this month has shown that taking a walk for about 20 minutes can reduce the risk of developing heart disease in middle aged people.