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Geisinger becomes the first member of Risant Health

Too much exercise could break your heart

Running a marathon, triathlon or even an “ultra” race longer than 26.2 miles is a long-term goal for many people. It’s a way to help maintain a healthy weight, build muscle and test your limits, both physically and mentally.
But there’s growing evidence that training for long race after long race could actually be detrimental to your health. For some male and female adults, long-term, intense aerobic training for endurance sports such as marathons, ultra-marathons and triathlons may have a negative effect on your heart.
“Endurance sports have become more popular in the past decade as more people seek to get and stay in shape, but there is some evidence that overtraining or chronic exercise can actually be detrimental to your health,” said Geisinger primary care sports medicine physician, Dr. David Ross.
During aerobic exercise, such as running, biking or swimming, your heart rate increases to pump more oxygenated blood to your muscles.
Competing in extreme endurance events such as marathons, ultramarathons, ironman distance events and long-duration bicycle events can cause abnormal volume shifts in the heart chambers (ventricles) with a temporary reduction in heart output. This ultimately results in the ventricles having to work harder for a longer period of time, therefore straining the heart. Typically, this function returns to normal within a week. But in some elite athletes, months to years of repetitive impact could lead to a potentially harmful heart condition known as myocardial fibrosis. Myocardial fibrosis, the scarring of the heart tissue, could lead to a lethal arrhythmia or, in its worst case, progress to heart failure.
In one study of male and female triathletes, researchers found that men were more prone to heart scarring and lasting effects of intense exercise and training compared to their female counterparts.
So, does this mean that exercise is bad for you?
“No, not at all,” said Dr. Ross. “There is a difference between exercising for health and training for a competition. The average person who gets the recommended amount of exercise—30 minutes a day, five days a week or more—is not likely to experience any negative effects of aerobic exercise.”
Even those people who regularly run half marathons and marathons or compete in sprint triathlons will not likely see negative effects of training. Taking appropriate rest days, following a training plan and getting enough sleep can help ensure that your body has enough time to recover after exercise.
However, this growing body of research underscores the importance of listening to your body and increasing the amount of exercise and intensity slowly over time.
If you’re new to aerobic exercise, you may want to try walking briskly for 10 or 20 minutes a day and increase the amount of time and intensity until you reach the recommend 150 minutes per week.
Before you start an exercise plan, you should visit your doctor—especially if you have diabetes, asthma or heart disease. 

“As with most things, you should exercise in moderation. Walk, run or bike, but give your body time to rest and heal, too,” noted Dr. Ross.
Primary care sports medicine specialist David Ross, MD, sees patients at Geisinger Orthopaedics, 1175 E. Mountain Blvd., Wilkes-Barre. To schedule an appointment with Dr. Ross, please call 800-275-6401 or visit


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