Which adaptation is associated with higher VO2 max?

Which adaptation is associated with higher VO2 max?

• A. Decreased capillary density
• B. Increased capillary density
• C. Increased fat mass
• D. Decreased stroke volume

Answer: (B)

VO2 max rises when the body's ability to deliver oxygen to muscles improves, and one key way this happens is by increasing capillary density in working muscles. With more capillaries around each muscle fiber, the diffusion distance for oxygen shortens and the surface area for exchange grows, so oxygen can reach mitochondria more efficiently at high intensities. That enhanced delivery supports a higher maximal rate of oxygen uptake during strenuous exercise. The other options don’t support this improvement: fewer capillaries would hinder oxygen delivery, adding fat mass doesn’t boost oxygen transport to the muscles, and a smaller stroke volume would limit the amount of blood (and thus oxygen) reaching the muscles. So, increasing capillary density is the adaptation most associated with higher VO2 max.

VO2 max rises when the body's ability to deliver oxygen to muscles improves, and one key way this happens is by increasing capillary density in working muscles. With more capillaries around each muscle fiber, the diffusion distance for oxygen shortens and the surface area for exchange grows, so oxygen can reach mitochondria more efficiently at high intensities. That enhanced delivery supports a higher maximal rate of oxygen uptake during strenuous exercise. The other options don’t support this improvement: fewer capillaries would hinder oxygen delivery, adding fat mass doesn’t boost oxygen transport to the muscles, and a smaller stroke volume would limit the amount of blood (and thus oxygen) reaching the muscles. So, increasing capillary density is the adaptation most associated with higher VO2 max.