In a small study, a year of exercise training helped to maintain or increase the youthful elasticity of the heart muscle among people in late middle age showing early signs of heart failure.
Published in Circulation, the research reinforces the notion that “exercise is medicine,” an important shift in approach, according to the researchers.
The study focused on heart failure with preserved ejection fraction, which is characterised by stiffening of the heart muscle and high pressures inside the heart during exercise. Once established, the condition is largely untreatable and causes fatigue, excess fluid in the lungs and legs, and shortness of breath.
“It is considered by some to be one of the most important virtually untreatable diseases in cardiovascular medicine,” said senior author Dr Benjamin Levine, professor of internal medicine at UT Southwestern and director of the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Dallas. “So, of course, if there are no therapies, then the most important thing to do is to figure out how to prevent it from happening in the first place.”
In previous studies, prolonged exercise training was shown to improve heart elasticity in younger people, but was ineffective for heart stiffness in people 65 and older. The researchers decided to see if committed exercise could improve heart stiffness in healthy, sedentary men and women ages 45 to 64.
The study recruited 31 participants who showed some thickening of the heart muscle and an increase in blood biomarkers associated with heart failure, even though they had no other symptoms such as shortness of breath.
Eleven were randomly assigned to a control group and prescribed a program of yoga, balance and strength training three times a week. The rest were assigned to an individually tailored exercise regimen that gradually ramped up until the participants were doing intensive aerobic interval training for at least 30 minutes at least twice a week, plus two to three moderate-intensity training sessions and one to two strength training sessions each week.
After one year, the group assigned vigorous exercise training showed a physiologically and statistically significant improvement in measures of cardiac stiffness and cardiorespiratory fitness, compared to no change in the control group.
The results suggest late middle age may be a “sweet spot” for using exercise to prevent heart failure with preserved ejection fraction, before the heart gets too stiff, Prof Levine said. He compared the heart muscle to an elastic band: a new one stretches easily and snaps right back.
“That’s a youthful cardiovascular system,” he said. “Now, stick it in a drawer and come back 30 years later—it doesn’t stretch, and it doesn’t snap back. And that’s one of the things that happens to the circulation, both the heart and the blood vessels as we age, particularly with sedentary aging.”
However, the study cannot determine if the participants will still go on to develop heart failure. This question will have to be addressed by larger studies. Furthermore, it is difficult for people to adhere to an exercise program, and the intensive intervention studied may be difficult and expensive to replicate on a large scale.
Source: American Heart Association
