What is cardiac hypertrophy?

Cardiac hypertrophy refers to the enlargement or thickening of the heart muscle, specifically the ventricular walls. This physiological change can occur as a response to various factors such as increased workload on the heart, which can often be seen in athletes during endurance training. When the heart experiences higher demands—such as during prolonged exercise—it adapts by increasing the size and strength of the muscle fibers, enabling it to pump more efficiently. This adaptation is generally a sign of improved cardiovascular fitness.

In contrast, other options do not accurately define cardiac hypertrophy. Enlargement of lung capacity pertains to respiratory function, while thinning of the heart walls and an increase in heart rate refer to different cardiovascular responses and conditions. Therefore, understanding cardiac hypertrophy highlights the body's ability to adapt to physical stress and improve its efficiency through structural changes in the heart.