Identify a true statement about afterload.

• A. Afterload Is Unchanged
• B. Afterload Increases With Training
• C. Afterload Is Reduced In Trained Muscles
• D. Afterload Not Related To Training

Answer: (C)

Afterload is the pressure the heart must overcome to eject blood into the aorta and the systemic circulation. It depends largely on arterial pressure and the resistance in the vessels (systemic vascular resistance). Regular training, especially endurance exercise, improves the vascular system by increasing arterial compliance and enhancing vasodilatory capacity in active muscles. These adaptations lower overall arterial resistance and often reduce resting and submaximal blood pressures. The result is that the heart does not have to generate as high a pressure to eject blood during exercise, meaning afterload is reduced in trained muscles. The other statements don’t fit with how training changes the vasculature and pressures: afterload isn’t typically unchanged or increased with training, and it is indeed affected by training through these vascular adaptations.