What to Know About Athletic Heart Syndrome (Athlete's Heart)

 It’s no secret that athletic endurance and strength go hand-in-hand with a healthy heart.

“Exercise strengthens the heart muscle, enabling it to pump a greater volume of blood with each heartbeat,” said Dr. Deepak Bhatt, editor of the Harvard Heart Letter, in a recent Q&A.

The enlarged heart muscles that athletes may develop are also the hallmark of a condition known as athletic heart syndrome (AHS), often called "athlete’s heart," according to the Cleveland Clinic.

When a person does vigorous-intensity exercise for more than an hour a day on the majority of days, changes in the heart may occur, according to the Cleveland Clinic. One of the main changes is thickening of the left ventricle wall. Another marker of AHS is that the space in your left ventricle gets larger.

A study of Olympic athletes published in Circulation: Cardiovascular Imaging revealed that AHS shows up differently in the hearts of women and men, although electrical and muscular size changes occurred in the hearts of both.

Athletic heart syndrome has no symptoms, according to the Cleveland Clinic. In fact, that's one feature that may distinguish AHS from serious heart disease or trauma. Chest pain, fainting, shortness of breath, and lower performance levels are all associated with serious heart conditions.

Even though AHS has no symptoms, “endurance athletes and other people who exercise a great deal often have lower-than-average heart rates, sometimes even below 40 beats per minute,” Bhatt said. “More oxygen gets delivered to the muscles, so the heart needs to beat fewer times than it would in a less-fit person while at rest.”

A study of more than 21,000 men published in JAMA Cardiology revealed that high-volume, high-intensity exercise did not raise the risk of heart disease in middle-aged male athletes.

“For the past decade or so, there's been increasing concern that high-volume, high-intensity exercise could injure the heart," lead researcher Dr. Benjamin Levine said in a news release on the study. "We found that high volumes of exercise are safe.” He's a sports cardiologist and professor of internal medicine at UT Southwestern Medical Center in Dallas.

While AHS is not dangerous to athletes’ health, it does share some features in common with certain heart conditions that may be harmful, according to the Cleveland Clinic. In particular, a set of conditions that affect the heart muscles, collectively known as cardiomyopathy, could be a reason for the heart’s size and electrical changes.

Since AHS is not considered a medical condition, no treatment is necessary, according to the Cleveland Clinic. Most athletes who want to reverse the syndrome can simply reduce their exercise training intensity and volume.

With athletic heart syndrome, you can expect your heart to stay healthy over the long term, making it one of the more positive "syndromes" known to science.

For more information on exercise and fitness, check out these additional resources:

How to Start Exercising: A Beginner’s Guide to Getting Started

Step Up! Here's How to Start a Healthy Walking Habit

5 Functional Strength Training Moves to Help Improve Your Everyday Well-Being

5 Moves for the Ultimate Calisthenics Workout, According to a Personal Trainer