A Heart-Smart Approach to Marathons and Vigorous Exercise

Marathons have never been more popular, with more than 550,000 runners crossing U.S. finish lines in 2014. So when recent headlines suggested that these endurance races may be linked to heart damage, the news rocked the running world. 


As an avid marathon runner, Johns Hopkins cardiologist Erin Michos, M.D., M.H.S., has closely followed the research on this trending fitness activity and its effects on the heart. Thus far, she says, there is far more compelling evidence in favor of endurance exercise than against it. Favorable effects on blood pressure, blood lipids, and body mass index have been reported with endurance training, and large studies show that people at higher levels of fitness are the least likely to die.

“I think it’s important not to scare people,” Michos says. “Exercise is good for people in general, and we don’t want to discourage athletes who are inclined to do endurance sports. More isn’t necessarily better, but it’s not necessarily harmful either.”

Here’s a plan to help you participate safely.

Choose Endurance Events for the Right Reasons

There’s no need to attempt a marathon or triathlon if your main goal is heart health, says Michos. The American Heart Association recommends just 150 minutes of moderate exercise or 75 minutes of vigorous activity each week. The good news for endurance athletes who enjoy extra activity: A large population study found that people engaging in three to five times the recommended minimum of physical activity had the best survival rates. Importantly, the researchers found no harm for those choosing to do 10 or more times the minimum amount.

Get a Heart-Health Checkup Before You Lace Up

A sudden death during or shortly after a marathon is very rare, but Johns Hopkins researchers found that most of these events occurred in people who had preexisting heart disease or a congenital heart problem. Bottom line: Before you ramp up your mileage, get clearance from your doctor, as Michos did. Discuss your health, heart disease risks, and training goals. Your doctor should ask about any symptoms such as chest pain or shortness of breath, ask about a family history of heart disease, measure your blood pressure, and listen to your heart with a stethoscope. He or she can perform the tests needed to determine how to proceed in the safest way possible for you.

Are the research results reason to worry?

One problem with the headline-making research is that these studies surveyed a very small group of marathoners, says Johns Hopkins cardiologist Erin Michos, M.D., M.H.S. They also weren’t structured enough to prove a cause-effect relationship between the sport and a negative health outcome. So even if a small group of marathoners have more calcium in their arteries, there’s no way of knowing why it’s there or whether it will raise their risk of heart problems later in life. Some people may be more vulnerable to the long-term effects of endurance training, but for the vast majority of healthy runners, endurance training appears to be safe.

Build Up Exercise Gradually

Look for a training program that helps you increase your mileage over time, and make your first event a 5K. Building up your mileage over time will reduce your risk of injury and increase your chances of sticking with the program.

Schedule Some Recovery Time

In a study of extreme cross-country skiing (90-kilometer events), finishers who went faster and completed a greater number of races had a higher risk of arrhythmias (irregular heart beat) during their lifetime. After a strenuous event or training session, allow your body time to rest and rebuild. Talk with your doctor about what is appropriate for you .

Fuel Workouts Healthfully

Shredding hundreds of calories with an extreme workout isn’t a license to binge on junk food. “It’s important to follow a heart-healthy diet ,” says Michos. “Make sure your intake replaces the fluid and calories you’ve lost during training.”

Listen to Your Heart

Some common red flags during exercise include chest pain, excessive shortness of breath, or an unusual amount of fatigue or difficulty completing a workout that was formerly doable. Ask your doctor what symptoms you should watch for during and after exercise, and learn what to do if they occur.

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