With the Rio Olympics in full swing, health and fitness are center stage. Fans may marvel at the intense training Olympic athletes have undertaken in order to prepare for this highly competitive event.
A possible side effect of this vigorous training is a condition known as athlete’s heart. This is a condition wherein, through ongoing strenuous exercise, the heart is enlarged, and exhibits a collection of structural and functional changes. Athlete’s heart occurs most frequently in athletes who train for an hour or more daily.
Athlete’s heart is not commonly dangerous and no treatment is required. But it is important to diagnose and differentiate as it can mimic more life-threatening heart ailments, such as hypertrophic cardiomyopathy. Other conditions that can be life-threatening to athletes can be ischemic heart disease or arrhythmogenic right ventricular dysplasia, some of which can exhibit similar signs.
People with athlete’s heart are usually asymptomatic. A physician might detect bradycardia — an abnormally low heartbeat — or a systolic murmur or other extra heart sounds. Abnormalities on an electrocardiogram (ECG) may also be seen. The pulse of a person with athlete’s heart can sometimes be irregular while at rest, but usually returns to normal after exercise begins.
Left ventricle muscle mass, wall thickness and chamber size are often increased in athlete’s heart due to volume and pressure loads. Structural changes in women are usually less than those in men of the same age, body size, and level of training.
Enlargement of the heart is caused by the heart’s needing to pump more blood through the body to counteract the oxygen deficit building in the skeletal muscles. The enlargement is a natural physical adaptation of the body to deal with the large amount of blood needing to be moved throughout the body.
The level and type of physical activity determine the physiological changes made by the heart. Static exercising such as weight lifting is mostly anaerobic, meaning the body does not rely on oxygen for performance. Dynamic exercises such as running, swimming and cycling rely on oxygen from the body and increase heart rate and stroke volume of the heart. With the heart being a muscle, it will in in this case become stronger by thickening or developing left ventricular hypertrophy. In general, strength training causes more thickening then endurance training. Once athletes stop training, the heart returns closer to its normal size.
So as you watch the Olympics tonight, remember that the athletes you’re cheering on might just have big hearts — not just because of the sacrifice they’ve made in the name of international competition, but because their hard work has actually increased the size of their hearts.