Experts say regular exercise can increase energy, burn calories and boost your overall heart health. But what about long-distance running? Recent news stories about marathon runners suffering from sudden cardiac arrest has led some to question the benefits and risks of such strenuous races.

Doctors at the Penn Sports Cardiology and Fitness Program say not to worry. Heart complications from running are actually quite rare when you look at the numbers. While any intense exercise can put strain on the heart muscle, research shows that running carries more benefit than risk.

According to the World Health Organization, adults ages 18 to 64 should exercise moderately for about 150 minutes or more intensely for 75 minutes on a weekly basis. For running, this would equal about eight miles a week at a nine-minute per-mile pace. To make sure your muscles are conditioned for the strain, it is also recommended to take time to add muscle-strengthening exercises to your workout routine at least twice a week.

A study published in JAMA Internal Medicine concluded that physical activity lowered the risk of death from heart disease by 40 percent, compared with the risks to people who were more sedentary.

When it comes to training for a more rigorous marathon or triathlon, doctors say it is important to train in a gradual manner to lower the risk of injury or heart complications. In other words, when in doubt, listen to your body.

What’s the takeaway message? Run at your own pace, train gradually and speak with your doctor about any possible heart problems before starting to train for your next big race.