Which statement best describes a long-term respiratory adaptation to regular aerobic training?

Which statement best describes a long-term respiratory adaptation to regular aerobic training?

• A. Breathing rate at rest decreases.
• B. Vital capacity decreases.
• C. Alveoli decrease in number.
• D. VO2 max increases.

Answer: (D)

Regular aerobic training strengthens the body's ability to take in, transport and use oxygen, and this shows up as an increase in VO2 max. VO2 max is the maximum rate at which the body can use oxygen during intense exercise, and it depends on how well the lungs exchange gases, how effectively the heart and blood vessels deliver oxygen, and how efficiently muscles use that oxygen. With sustained training, the heart can pump more blood per beat, capillaries in the muscles grow, and muscle cells become better at using oxygen due to more mitochondria. All these changes raise the maximum oxygen uptake, so VO2 max increases. The other statements don’t capture this integrated improvement: resting breathing rate isn’t the key long-term change, vital capacity tends to improve rather than decrease, and alveoli don’t decrease in number with training.

Regular aerobic training strengthens the body's ability to take in, transport and use oxygen, and this shows up as an increase in VO2 max. VO2 max is the maximum rate at which the body can use oxygen during intense exercise, and it depends on how well the lungs exchange gases, how effectively the heart and blood vessels deliver oxygen, and how efficiently muscles use that oxygen. With sustained training, the heart can pump more blood per beat, capillaries in the muscles grow, and muscle cells become better at using oxygen due to more mitochondria. All these changes raise the maximum oxygen uptake, so VO2 max increases. The other statements don’t capture this integrated improvement: resting breathing rate isn’t the key long-term change, vital capacity tends to improve rather than decrease, and alveoli don’t decrease in number with training.