Endurance training leads to increased capillarization in skeletal muscle. What is the primary benefit?

Endurance training leads to increased capillarization in skeletal muscle. What is the primary benefit?

• A. Capillary density increases around muscle fibers, improving oxygen delivery and metabolite clearance
• B. Capillary density decreases
• C. Capillaries become less efficient at oxygen delivery
• D. Capillary density remains unchanged

Answer: (C)

Endurance training promotes the growth of new capillaries around skeletal muscle fibers, increasing capillary density. This expanded network shortens the distance for oxygen to travel from blood to the mitochondria and enhances the removal of metabolic byproducts such as carbon dioxide and lactate. With more capillaries supplying blood and more surface area for exchange, aerobic metabolism can proceed at higher rates for longer and fatigue is delayed. So the primary benefit is improved oxygen delivery to muscle fibers and faster metabolite clearance, supporting sustained endurance performance. This capillary growth results from the training stimulus activating factors like VEGF that drive angiogenesis.

Endurance training promotes the growth of new capillaries around skeletal muscle fibers, increasing capillary density. This expanded network shortens the distance for oxygen to travel from blood to the mitochondria and enhances the removal of metabolic byproducts such as carbon dioxide and lactate. With more capillaries supplying blood and more surface area for exchange, aerobic metabolism can proceed at higher rates for longer and fatigue is delayed. So the primary benefit is improved oxygen delivery to muscle fibers and faster metabolite clearance, supporting sustained endurance performance. This capillary growth results from the training stimulus activating factors like VEGF that drive angiogenesis.