Along with following a nutritious diet and avoiding risky behavior like smoking, part of a healthy lifestyle includes exercising regularly. But two new studies published in the journal Heart suggest doing too much high-intensity exercise may increase risks of dying from a heart attack or developing an irregular heart rhythm later in life.
In a linked editorial to the studies, two writers say the results reveal a “J-shaped curve” for health benefits of exercise, whereby more does not always mean better. They also say the research raises questions about intensity and duration of physical activity at different points in life.
The first study was conducted by researchers in Germany, who, for 10 years, assessed the frequency and intensity of physical activity in more than 1,000 individuals with stable coronary artery heart disease for 10 years.
Participants were mostly in their 60s and had participated in a cardiac rehabilitation program to help them exercise regularly. The researchers tracked survival of all participants as part of the study.