When a participant in a major event like a sportive or marathon suffers a heart attack, it makes headlines. But there's no need for MAMILs and MAWILs to panic: a new study shows middle-aged athletes are at low risk for having a sudden cardiac arrest while playing sports, and those who do have a greater chance of surviving.

"Because there is so much media attention when someone has a sudden cardiac arrest while playing sports, we want to make sure people know that the benefits of exercise far outweigh the risk of having a cardiac arrest," says Sumeet S. Chugh, MD, an expert in heart rhythm abnormalities.

"Even for middle-aged men, who are more susceptible to heart rhythm disturbances, the risk is quite low."

Dr Chugh is associate director of the Cedars-Sinai Heart Institute, Los Angeles California and one of the authors of the paper Sudden Cardiac Arrest During Sports Activity in Middle Age, published in the journal Circulation.

In the study, investigators studied the 1,247 people aged 35-65 from the Portland, Oregon, metropolitan area who had a sudden cardiac arrest between 2002 and 2013. Results include: Just 5 percent, or 63 people, had a sudden cardiac arrest during sports activities.

The study also found that the survival rate of 23 percent was markedly higher for those who had a sudden cardiac arrest while exercising compared to just 13 percent for those who had a sudden cardiac arrest during other activities.

That higher survival rate is likely to be down to the sporting environment though. Cardiopulmonary resuscitation (CPR) was applied to 87% of those who had a sudden cardiac arrest while engaged in sports, but only 53% of those who had a cardiac arrest during other activities.

Although "sudden cardiac arrest" and "heart attack" often are used interchangeably, the terms are not synonymous. Unlike heart attacks (myocardial infarctions), which are typically caused by clogged coronary arteries reducing blood flow to the heart muscle, sudden cardiac arrest is the result of defective electrical activity of the heart. Patients may have little or no warning, and the disorder usually causes instantaneous death.

"The chance of surviving sudden cardiac arrest is better if the episode occurs while exercising, probably because there are likely to be others around who can do chest compressions until paramedics arrive," said Chugh.

"What this study shows is that most middle-aged athletes don’t need to worry about sudden cardiac arrest while they are working out," Chugh said. "As our population ages, it’s important to know that older people can exercise without worrying about triggering a heart rhythm disturbance."

And if you don't know how to perform CPR, you might want to learn how.