Myocarditis Exercise Recommendations

And the importance of following activity restrictions

Myocarditis, an inflammation of the heart muscle, is one of the cardiac conditions associated with sudden death in young athletes. Significantly restricting exercise is necessary to reduce potential complications, including the risk of sudden death. 

Exercise restrictions can be frustrating for young athletes. Because this condition often has no early symptoms, you may feel well enough to compete, and you may be tempted to disregard medical advice. Ignoring your healthcare provider's instructions, however, can be very dangerous.

Young athlete hurdling
Henrik Sorensen / Getty Images

The risk of exercise-induced sudden death is real even with mild cases of myocarditis. It is critical that young athletes restrict their athletic activities until given an "all clear" by their cardiologist.

When it may be possible to ease back into exercising depends on many factors. This article discusses some of these basic guidelines and what an active life with myocarditis might look like.

Myocarditis Overview

Myocarditis is an inflammatory disease of the heart muscle. It can have numerous underlying causes, including:

Often, no specific underlying cause can be found. When this happens, the myocarditis is said to be idiopathic.

Symptoms of myocarditis can vary widely. The severity of symptoms often depends on the degree of inflammation present in the heart and the amount of heart muscle damaged by the inflammation.

When myocarditis is severe and affects a large portion of the heart muscle, it can lead to cardiomyopathy and heart failure. This is usually accompanied by symptoms such as:

  • Dyspnea (shortness of breath)
  • Fatigue
  • Weakness
  • Edema (swelling)

Sometimes, myocarditis affects only small portions of the heart muscle. In these cases there may be only very mild symptoms, such as:

  • Mild weakness
  • Fatigue

Sometimes, the only symptom is chest pain during exercise. In some cases of myocarditis, there are no symptoms at all.

Myocarditis may occur as a very acute or chronic illness. This means it may happen suddenly and be present for only a short time, or it may be long-term.

There are a number of tests that are used to diagnose myocarditis, including an electrocardiogram (ECG). In many cases, however, the first and only indication of myocarditis is sudden death.

After Your Diagnosis

If you are diagnosed with myocarditis, you should completely avoid all sports for up to six months or longer. Resume activity only if cardiac tests show complete recovery.

Exercise of any kind should be avoided until your healthcare provider confirms you have no abnormal heart rhythms and your left ventricle is functioning normally. The left ventricle is the large heart chamber that pumps blood to the rest of the body. Your healthcare provider will also want to make sure there are no signs of persistent inflammation or scar tissue.

There are many other factors that will need to be considered before you can resume exercise, including:

  • The possible cause of the myocarditis
  • If the myocarditis was temporary or progressive

Some causes of myocarditis increase the risk of sudden death much more than others.

Easing Into Exercise

It can be beneficial to resume moderate exercise once your cardiologist determines it is safe. At this point, any exercise will need to be done only under the guidance of your cardiologist.

Your cardiologist will help you ease back into exercising with an exercise plan that is tailored to your particular situation. Cardiac rehabilitation is often the starting point since your activity can be safely monitored when you are in a controlled setting.

Once you're cleared to return to exercise, you will likely be limited to moderate activities for several weeks or months. Extreme exercise may worsen the heart-damaging effects of viral myocarditis and should be avoided.

Competitive Exercise

You will be able to return to competitive exercise only under the guidance of your cardiologist. In many cases, athletic competition will have to be delayed for at least six months, sometimes much longer.

Before you can go back to competitive activity, you will be thoroughly evaluated with the following tests:

Some cardiologists may also recommend a heart MRI, though the benefit of this is not certain at this time.

Athletes who have scarring of the heart may be at greater risk of abnormal rhythms and sudden death. For these people, a return to competition may not be recommended.

Long-Term Outlook

Whether you will be able to return to exercise for the long term will depend on the cause of your myocarditis and whether there is permanent damage to your heart. Many viral causes of myocarditis are self-limited, but they can cause long-term damage. This could mean you'll need to restrict physical activity going forward.

Summary

If you have been diagnosed with myocarditis, you will need to completely avoid exercise until your cardiologist says it is safe. This often means avoiding all physical activity for six months or more.

You should resume moderate exercise only after you are cleared to do so by your cardiologist. At first, you will need to closely follow the exercise plan your cardiologist created for your specific situation. This is usually done in a supervised cardiac rehabilitation setting.

How much exercise you will be able to do going forward depends on the extent of your myocarditis and whether there was any permanent damage to your heart. Remember that failing to follow your cardiologist's recommendations could have severe consequences, including sudden death.

A Word From Verywell

As you return to exercise, make sure you understand what you should and should not do, and what precautions you need to take in order to stay safe. You should also know what symptoms may indicate that an activity is too much for your heart.

Young athletes with even mild myocarditis are those most prone to sudden death during athletic events. Too much exercise may also put a child with myocarditis at risk of permanent heart damage and disability.

Myocarditis often develops at a time when young people are trying to become independent and make their own decisions. This is why it's so important that young athletes understand the risks of not following their cardiologist's instructions. If you are a parent of a child with mild myocarditis, make sure your child is as familiar with their cardiologist's exercise recommendations as you are.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Tschöpe C, Cooper LT, Torre-Amione G, Van Linthout S. Management of myocarditis-related cardiomyopathy in adults. Circ Res. 2019;124(11):1568-1583. doi:10.1161/CIRCRESAHA.118.313578

  3. Maron BJ, Udelson JE, Bonow RO, et al. Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: Task Force 3: hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and other cardiomyopathies, and myocarditis: a scientific statement from the American Heart Association and American College of CardiologyCirculation 2015;32:e273. doi:10.1161/CIR.0000000000000239

  4. Shaw N, Phelan D. Myocarditis in the athlete.

Additional Reading

By Richard N. Fogoros, MD
Richard N. Fogoros, MD, is a retired professor of medicine and board-certified in internal medicine, clinical cardiology, and clinical electrophysiology.