Regular Aerobic Activity Can Rejuvenate Previously Sedentary Hearts

If you’re in your 50s or early 60s and you’ve lived a largely sedentary lifestyle, your heart just isn’t what it used to be. It’s not as strong, the muscle is getting stiffer, and the risk of heart failure is increasing. But there’s good news, according to a study published in the journal Circulation: a program of regular cardiovascular exercise begun in middle age could be enough to reverse the negative effects of a lifetime on the couch.

The study followed a small group of healthy, previously sedentary, middle-aged participants. Half of the group was placed in an exercise program that gradually built up to a regular routine of aerobic training in a variety of both indoor and outdoor activities (swimming, biking, running, etc., including weekly high intensity interval sessions), supplemented by strength training. The other half was placed in a control group that performed balance, flexibility, and strength training without any prolonged endurance activity.

For two years, study participants were monitored for compliance with their assigned exercise programs. Periodic measurements were taken charting changes to a variety of heart health markers.

And the results? At the end of the two-year study, the aerobic exercise group showed a significant reduction in left ventricle chamber and myocardial stiffness, while there was no improvement for the non-aerobic group.

“I was astounded at how well this seemed to improve the flexibility and compliance of the heart,” said Dr. Benjamin Levine, one of the researchers on the study. “The key to a healthier heart in middle age is the right dose of exercise at the right time in life.”

That dose turns out to be four to five times per week for a total of about 150 minutes of activity. That includes at least one long exercise session; one high-intensity interval workout as short as 20 to 30 minutes; one or two strength training sessions; and two to three days of moderate intensity exercise such as a brisk walk.

“We found that exercising only two or three times a week didn’t do much to protect the heart against aging,” Levine said. “But committed exercise four to five times a week was almost as effective at preventing sedentary heart aging as the more extreme exercise of elite athletes.”

One precaution about starting exercise later in life, though, is that the people in this study, despite their previously sedentary lifestyle, were all considered healthy at the start. People were excluded from the study if they already had conditions such as hypertension, obesity, or pulmonary or coronary artery disease. That’s not to say these “excluded” groups would not benefit from exercise, but care must be taken and personal physicians should be consulted before beginning any program that might aggravate existing conditions. And so while some people can get away with waiting until middle age to start an exercise program, most people are better off starting sooner rather than later — before this whole host of other health conditions has a chance to take hold. 

Another interesting and hopeful bit of news related to this study is the issue of compliance. Participants were given a calendar specifying the workouts they should perform, but for most of their exercise sessions they were on their own. Still, the vast majority of participants managed to stick with the plan through the two-year study period, and even came to enjoy it. That’s remarkable considering how often people begin new exercise programs but fail to follow through. What was different about this one? It could be the additional accountability people felt because of their regular check-ins with program supervisors; it could be the structured but flexible program they were offered; it could be the gentle lead-in as they slowly developed fitness before advancing to more strenuous activities. We can’t say for sure, but these are all things to consider as we commit to our own new exercise programs. Developing your own support team including your personal doctor, trainer or physical therapist can only make things easier.

The bottom line, once again, is that exercise is critically important to our health, and it becomes even more so as we age.