Heart attack survivors should start exercising days after suffering cardiac arrest to give themselves the best chance of recovery, according to a new study.

The research, published in the American Journal of Physiology–Heart and Circulatory Physiology, notes the benefits of exercise in preventing heart attacks and concludes that exercise could also be key to recovering from them.

After a heart attack, restoring blood flow to the oxygen-starved region of the heart is not enough to make the heart function normally again. The affected area scars and thins, and the heart changes structurally. Because of the remodelling and loss of working heart muscle, heart attack survivors can develop other heart complications.

The team of researchers from Germany and Luxembourg found that aerobic exercise can reduce the scarring, thinning and structural changes, improving recovery success in physically active individuals.

For the study, mice ran on a wheel regularly for six weeks prior to heart attack induction, then resumed activity five days after heart attack and continued exercising for four more weeks.

Compared to sedentary mice, the hearts of the exercising mice had less heart attack-induced scarring, thinning and inflammation.

“Our results suggest that the re-initiation of exercise can be recommended to patients relatively early” after heart attack, the researchers wrote.

That exercise is key to heart attack recovery is all the more pertinent given that another recent study published in JAMA Internal Medicine revealed that most older adults who are hospitalised for a heart attack in the US do not attend even one of the recommended cardiac rehabilitation sessions. The study authors concluded that although a few patients may be too vulnerable to exercise, the bulk of older adults would significantly benefit from attending post-heart attack exercise sessions.