What effect does aerobic exercise have on cardiac muscle?

Aerobic exercise plays a significant role in influencing the structure and function of cardiac muscle. When engaging in regular aerobic activities, such as running, cycling, or swimming, the heart undergoes physiological adaptations to accommodate the increased demands for oxygen and blood flow during prolonged exercise.

One of the primary effects of aerobic training is an increase in the size of the heart, specifically the left ventricle, which leads to hypertrophy. This adaptation allows the heart to pump more efficiently, delivering greater volumes of blood with each beat, ultimately resulting in improved cardiac output. As a result, the heart becomes more adept at meeting the higher oxygen and nutrient demands of the working muscles during prolonged physical activity.

Increased cardiac size due to aerobic exercise is a positive adaptation, indicating that the cardiovascular system is becoming more efficient. This eccentric hypertrophy is different from the concentric hypertrophy seen in strength training, where the heart might increase in wall thickness without significantly increasing volume.

With this understanding, it becomes clear that the option referring to an increase in cardiac muscle size (hypertrophy) is indeed the correct answer, as it encapsulates the primary cardiovascular adaptation associated with regular aerobic exercise.