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 understand how much exercise an individual needs to perform in order to prevent their heart and blood vessels from aging.
Building on previous research which shows that exercise cuts the risk of heart disease, the researchers found that varying amounts of exercise affect 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 less 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 the results of their study may have been limited by participants being categorized according to their exercise levels rather than factors such as the type of exercise, demographic data and lifestyle choices which also play a large role in development of cardiovascular disease.
The study could be used to create exercise programs designed to protect heart health, the scientists argued, 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, and the 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 authors of the study at the Institute for Exercise and Environmental Medicine in Dallas, 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." He said that 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 focussing 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."