It is understandable that people who have had a heart attack feel fragile, but physical activity is an important part of recovery after a heart attack. Many patients who have had a heart attack don't sign on for the recommended amount of exercise in the weeks after hospital discharge, according to a recent study. And this can affect their recovery.

“Before we had modern treatments for heart attacks and a better understanding of physical activity and rehabilitation after heart attacks, patients used to be advised to stay in bed for weeks,” Ian Kronish, lead author of the study, told TheDoctor. So many patients still think they need to rest when they go home.

The American College of Cardiology and the American Heart Association recommend heart patients get at least 30 minutes of moderate aerobic activity, such as brisk walking, at least five days per week within two weeks of leaving the hospital.

There's psychology involved too, he added. Many patients fear if they put too much strain on their heart they will have chest pain or another heart attack.

To get a clear picture of how much or how little heart patients were exercising, Kronish and his team fit 620 patients who had had a heart attack with a wearable activity monitor. Of those 620 patients, 330 returned the device with sufficient data. Previous studies relied on patients' self-reports of exercise and gave an unreliable estimate of how many patients achieved their exercise goals. “Objective measurement was necessary,” said Kronish, the Florence Irving Assistant Professor Medicine at Columbia University Medical Center in New York City.

Physician-supervised exercise programs, or cardiac rehabilitation, have been shown to reduce patients’ fears about exercising again, while encouraging them to be physically active. Kronish was surprised to find that so few patients take advantage of them.

Doctors need to be more aggressive about finding ways to get more patients to participate, said Kronish. “For patients who have anxiety about straining their heart, and want that extra care, [rehab] programs are a really good way for them to feel secure knowing health professionals are monitoring them as they start exercising again,” he said.

The American College of Cardiology and the American Heart Association recommend heart patients get at least 30 minutes of moderate aerobic activity, such as brisk walking, at least five days per week within two weeks of leaving the hospital.

Kronish said the best type of exercise might be different for different people. “People who are in better shape when they have a heart attack could jog or go for a bike ride,” he said.

The study is published in the Journal of the American College of Cardiology.