Regular cardiovascular activity increases VO2 max due to increased alveoli and capillaries in the lungs.

Regular cardiovascular activity increases VO2 max due to increased alveoli and capillaries in the lungs.

• A. Decreased Alveoli And Capillaries
• B. Increased Alveoli And Capillaries
• C. No Change In Lung Structures
• D. Reduced Oxygen Transfer

Answer: (B)

Regular aerobic training boosts how efficiently oxygen moves from the air into the blood by increasing the surface area and network for gas exchange in the lungs. More alveoli and a denser capillary bed around them mean a greater diffusion capacity, so more oxygen enters the blood during maximal exercise. That enhanced oxygen uptake supports a higher VO2 max. If alveoli and capillaries were reduced or unchanged, diffusion would not improve, and VO2 max would not rise with training. Reduced oxygen transfer would lower VO2 max. So increasing alveoli and capillaries best explains the improvement.

Regular aerobic training boosts how efficiently oxygen moves from the air into the blood by increasing the surface area and network for gas exchange in the lungs. More alveoli and a denser capillary bed around them mean a greater diffusion capacity, so more oxygen enters the blood during maximal exercise. That enhanced oxygen uptake supports a higher VO2 max. If alveoli and capillaries were reduced or unchanged, diffusion would not improve, and VO2 max would not rise with training. Reduced oxygen transfer would lower VO2 max. So increasing alveoli and capillaries best explains the improvement.