How Much Exercise Will Keep Your Heart Healthy? Scientists May Have the Answer

It's common knowledge that exercise keeps hearts healthy, but now scientists believe they have pinpointed the exact amount of time we need to spend working out in order to look after our tickers. 

As we grow older, our arteries can stiffen and make us prone to heart disease, especially if we are inactive. The researchers based in Texas therefore wanted to know how much exercise individuals needed in order to prevent their heart and blood vessels from aging. 

Building on previous research showing that exercise cut the risk of heart disease, the researchers found that varying amounts of exercise affected arteries of varying sizes differently.

Exercising for 30 minutes two to three days per week was found to keep the middle-sized arteries, which supply the head and neck, from aging. But the larger arteries, which send blood to the chest and abdomen, benefit from the same amount of exercise four to five days per week.

The researchers made their findings by carrying out a cross-sectional analysis of 102 people aged 60 years old and over, who were grouped into four categories: sedentary (defined as fewer than two 30-minute exercise sessions per week for the past 25 years); casual (two to three sessions); committed exercisers (four to five sessions); and master athletes (six to seven). The team then logged levels of stiffness in their arteries.

Casual exercise was found to be enough to keep the middle-sized arteries youthful, but those who completed four to five sessions a week had younger-seeming large central arteries. 

The authors acknowledged that the results of their study may have been limited by participants being categorized according to their exercise levels rather than factors such as type of exercise, demographic data and lifestyle choices, all of which play a major role in the development of cardiovascular disease.

The study could be used to create exercise programs designed to protect heart health, the scientists stated, while further research could reveal whether exercise can reverse heart-aging. 

Researchers from the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and the University of Texas Southwestern Medical Center at Dallas, the John Peter Smith Health Network, Texas Christian University and University of North Texas Health Science Center collaborated on the research, published in The Journal of Physiology.

Benjamin Levine, one of the Institute for Exercise and Environmental Medicine in Dallas authors, said in a statement: "This work is really exciting because it enables us to develop exercise programs to keep the heart youthful and even turn back time on older hearts and blood vessels."

Levine also said previous studies have shown that waiting until the age of 70 to reverse heart-aging is too late. 

"It is difficult to change cardiovascular structure even with a year of training," he said. “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 aging of a heart and blood vessels by using the right amount of exercise at the right time." 

Maureen Talbot, senior cardiac nurse at the charity the British Heart Foundation, told Newsweek: "This small study reinforces that sedentary behavior seriously impacts our cardiovascular health and increases our risk of heart attack and stroke. In fact, physical inactivity has become one of the most significant global health crises of the 21st century. 

"It’s interesting to hear that exercising four to five times a week could potentially slow progression of artery stiffness and reduce the risk of heart attack and stroke. But a larger study is needed to confirm these findings."

Talbot continued that there are many ways people can keep active, from running with their dog to walking home from work. "Just a little exercise is better than none. The important thing is to find a form of exercise you enjoy, so that you make time for it in your weekly routine."

This article has been updated with comment from Maureen Talbot.