Athletic Training Practice Exam

During prolonged training, which cardiac change is most likely to occur over time?

1. Development of heart murmurs

2. Increase in heart size

3. Development of premature ventricular contractions

4. Mitral valve prolapse

The correct answer is: Increase in heart size

Over time, prolonged training, especially endurance activities such as running or cycling, leads to what is known as "athlete's heart." This adaptation is characterized by an increase in the size of the heart, particularly in the left ventricle, as a response to the elevated demands placed on the cardiovascular system during regular intense exercise. The enlarged heart can pump more blood with each beat, enhancing cardiac output and improving overall athletic performance. This physiological adaptation allows for more efficient oxygen delivery to the muscles, which is crucial during extended periods of exertion. The increase in heart size is generally healthy and is distinguishable from pathological conditions, as it results from adaptive changes rather than disease processes. Other options presented are less likely to be direct outcomes of prolonged training. Heart murmurs and premature ventricular contractions may occasionally be observed but are not typical adaptations to consistent and prolonged training. Similarly, while mitral valve prolapse can occur in some individuals, it is generally not directly associated with the adaptations seen in response to prolonged exercise.