A new study shows that contrary to previous belief, even elderly heart patients can benefit from regular exercise.
Dr. Stephan Gielen, deputy director of cardiology at the University Halle/Wittenberg in Germany, and his colleagues say that physical activity can help protect heart patients over age 70 from muscle wasting, a condition that in many cases can worsen these patients’ health and impede their recovery.
Over the course of a lifetime, muscle is constantly made and degraded, and with age, the deterioration becomes dominant, leading to weakness and difficulty in maintaining cardiac and respiratory health. In previous studies, Gielen and his colleagues showed that inflammation, which can occur after heart failure, can accelerate the wasting of muscle, so in the current study, they wanted to document what effect, if any, exercise might have on this process.
Gielen and his team recruited 60 patients with heart failure and 60 healthy controls, each in two age groups: people 55 years old and younger, and those 65 and older. Half the participants in each age group were assigned to a four-week aerobic exercise program of stationary cycling; each participant cycled for 20 minutes, four times a day on weekdays, and also had a 60-minute group exercise session involving walking and calisthenics. The other half received the usual clinical care by their physicians.
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To study changes in muscle physiology, the researchers took biopsies of muscle from each participant’s leg and analyzed them for certain enzymes related to muscle maintenance. After the four weeks, as the researchers report in the journal Circulation, those in the exercise group showed marked improvement in their muscle enzymes; they showed lower levels of a muscle breakdown protein than those who didn’t exercise, even though the heart patients had higher levels of this protein to start.
The exercise participants also showed lower levels of inflammation in the muscle, and increased muscle strength. This translated to physiological benefits as well; the heart failure patients under age 55 increased their peak oxygen intake by 25%, while those over age 65 increased this measure by 27%. The key is an enzyme system that monitors the balance between muscle strengthening and degradation, and exercise can tip the balance in favor of muscle strengthening.
“What surprised us was the speed of onset of these effects,” says Gielen. “We believed that with a short term program of four weeks, the effects would be much more limited. But it was surprising for us that we got nearly all the effects of exercise training after just four weeks. So this is a very rapid system, and even at advanced ages, there is a high plasticity of the muscle system.”
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That means that regardless of age, says Gielen, heart patients can benefit from exercise, and rather than worsening their condition, as doctors intuitively thought for decades, physical activity actually improves their health and may even speed their recovery. Gielen and his team studied the benefits only of aerobic exercise on muscle mass, but other studies have also hinted that weight-bearing or resistance training can also help elderly patients maintain their muscular strength.
Having a potential regulatory pathway also makes it possible to develop drug targets that may boost muscle conditioning, says Gielen, if additional studies confirm these results. “This plasticity of the muscle system is underused in medicine at the moment,” he says. But perhaps not for much longer.
Alice Park is a writer at TIME. Find her on Twitter at @aliceparkny. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.