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Dr. Molly Ware on Heart Problems in Athletes

Dr. Molly Ware on Heart Problems in Athletes

Plus, how COVID-19 can increase your risk

Boulder is considered one of the fittest communities in the nation. We have an impressive number of professional athletes and a multitude of recreational athletes, many who train and compete at an elite level.

But demanding workouts can trigger physiologic changes in the heart that can intensify an undetected heart problem. Without diagnosis and treatment, certain heart problems can be life threatening.

Cardiac disease specialists Drs. Molly Ware and Samuel Aznaurov presented a free two-part online Boulder Community Health lecture on “Recognizing and Treating Heart Problems in Athletes.” In part one of the lecture, described here, Dr. Ware provided an overview of how exercise can spark changes to the heart and cause heart-related issues that commonly impact athletes. She also explained how Covid-19 can affect your heart.

In part two, Dr. Aznaurov discussed irregular heartbeats, unexplained temporary loss of consciousness and cardiac arrest in athletes.


VIDEO: Watch "Recognizing and Treating Heart Problems in Athletes."


Benefits of Exercise

Dr. Ware began by acknowledging, “Exercise is good for us and is really the best medicine available for battling chronic disease. The fitter we are, the lower our risk of dying from cardiovascular disease and the more likely we are to live longer.”

She highlighted that exercise results in:


  • cardiovascular health
  • musculoskeletal (muscle and bone) health
  • metabolic health (keeping blood pressure, blood cholesterol and glucose under control)


  • inflammation
  • risk of cancer
  • mental health related issues

“However, the benefits of exercise,” Dr. Ware noted, “plateau at about 100 minutes per day.”

Changes to the Heart in Trained Athletes
Dr. Ware spoke about how athletes’ demanding workouts can trigger physiological changes to the heart. These changes arise from an increase in heart rate and stroke volume (the amount of blood squeezed from the heart with each heartbeat) during high-endurance activity.

She stated, "The heart adapts to intense exercise by pumping more blood per stroke. For the average individual, stroke volume is about 5 to 6 liters per minute at rest; it can increase to 35 liters per minute for a well-trained athlete during high intensity exercise.”

Understanding what happens to our bodies as we begin to exercise helps us understand the issues athletes and active people can face. Dr. Ware explained that as we begin to exercise our:

  • brain and nervous system (our control center) kick on
  • cardiac output increases
  • blood pressure goes up to improve perfusion (blood flow) to our working muscles
  • rate and depth of breathing increases
  • muscles extract more oxygen from the blood more efficiently during the VO₂ process. (VO₂ refers to how much oxygen your body can absorb and use during exercise. It’s commonly used to test the aerobic endurance or cardiovascular fitness of athletes before and at the end of a training cycle.)

Dr. Ware emphasized, “Because of the many physiological changes that occur during exercise, we strongly recommend that athletes of all levels warm up before every training session. This allows a gradual rise in our blood pressure.”

Common Heart Problems in Athletes

Dr. Ware described some of the common heart-related issues that can potentially impact athletes. She provided insight on:

  • Coronary artery disease (CAD)
  • Heart valve issues
  • Aortic disease
  • Covid-19 and how it can affect the heart

Coronary Artery Disease (CAD)
Dr. Ware explained, “Our coronary arteries feed our heart muscle and it’s not uncommon to experience CAD, the buildup of plaque inside of our vessels.” This buildup narrows our arteries resulting in decreased blood flow to our heart. Eventually the reduced flow may cause chest pain (angina) and shortness of breath. A complete blockage can cause a heart attack.

Masters endurance athletes, especially those older than 50, are not immune to CAD. Dr. Ware said, “When we evaluate athletes, we need to understand if they have family history of heart disease, high blood pressure and/or untreated high cholesterol. These underlying risk factors can increase their chances of having plaque buildup.”

She added, “In fact, research indicates that master endurance athletes have a higher incidence of plaque buildup and men are more affected than women.”

Heart Valve Issues

Dr. Ware explained, “The heart has four valves that act as doors that open and close. They allow blood to move forward as the heart squeezes and relaxes. The valve most commonly affected and that we worry about especially in athletes is the aortic valve.” Some people will experience a narrowing of this valve. “This narrowing puts pressure on the pumping chamber and potentially can cause heart failure.”

She emphasized that your doctor will absolutely want to know if, as an athlete, you’re experiencing trouble breathing, swollen legs, decreased athletic performance, fainting or an irregular heartbeat.

Aortic Disease

Aortic problems are usually caused by high blood pressure or genetic syndromes and can lead to dissection or rupture of the aorta. Dr. Ware explained, “People who are experiencing aortic issues and who participate in activities that result in their blood pressure increasing very quickly, such as heavy weightlifting or high intensity intervals, may need to modify their activities to avoid further dilation.”

Covid-19 and the Risk of Heart Problems

While the data is still evolving, Dr. Ware explained that, generally, people with no or very mild COVID-19 symptoms are highly unlikely to have any cardiac complications. “However, nearly a quarter of patients who were hospitalized with severe Covid-19 illness developed some cardiac problem,” Dr. Ware warned.

Covid-19 can affect the heart and increase the risk of:

  • heart attack,
  • stroke,
  • pulmonary embolism (a blockage in one of the pulmonary arteries in the lungs),
  • myocarditis (an inflammation of the heart muscle)

Dr. Ware strongly encourages anyone who has received a positive Covid-19 test result to take at least 10 days off from exercising. “If you have experienced moderate or prolonged symptoms and aren’t getting back to normal,” Dr. Ware said, “definitely reach out to your health care provider, take it slowly and follow the 10-day rule of gradually returning to physical activity.”

Dr. Ware also provided the following guidelines:

• If you have NOT experienced symptoms during or after a Covid-19 infection there is no need to evaluate your risk for developing cardiovascular disease. Monitor your symptoms.

• If you experience moderate or severe disease and cardiac symptoms such as chest pain, palpitations, syncope (sudden, often unexplained and temporary loss of consciousness), shortness of breath and exercise intolerance, be sure you are evaluated by a health care provider and consider a cardiology referral.

• If you have experienced myocarditis, this warrants a careful return to play and attention to myocarditis guidelines as well as a consultation with a multidisciplinary team.

• Masters athletes, especially those with pre-existing heart conditions and/or moderate to severe Covid-19, should be evaluated by a cardiology expert and follow a graduated return to play and activity protocol.

Dr. Ware stressed, “It’s important to take Covid-19 seriously and get vaccinated if you can.”

Detecting — or Ruling Out — Heart Disease in Athletes
Make an appointment with a Boulder Heart cardiologist if you’re an athlete and experience any of the following symptoms:

  • Fainting
  • Chest pain or pressure
  • Unusual shortness of breath
  • Unusual heart racing/skipping
  • Unexplained decline in exercise tolerance

Boulder Heart uses the latest heart technologies to diagnose potential heart problems in athletes, including imaging and stress tests. They can also evaluate whether your symptoms are related to physical activity or something more serious.

To make an appointment with a Boulder Heart cardiologist, call (303) 442-2395.

Click here to view/download a PDF of slides shown during this lecture.