After altitude acclimation, which adaptation commonly improves sea-level performance?

After altitude acclimation, which adaptation commonly improves sea-level performance?

• A. Decreased haemoglobin concentration
• B. Increased red blood cell count and haemoglobin
• C. Decreased lung diffusion capacity
• D. Lower VO2max

Answer: (B)

Altitude exposure prompts the body to boost oxygen-carrying capacity by increasing red blood cell mass and haemoglobin concentration. When you’re at high altitude, the lower oxygen availability stimulates the kidneys to release erythropoietin, which drives more red blood cell production. More red blood cells and more haemoglobin mean each millilitre of blood can carry more oxygen, raising arterial oxygen content. On return to sea level, this extra capacity helps deliver more oxygen to working muscles during intense exercise, supporting higher performance, especially in endurance activities. If haemoglobin were decreased, oxygen transport would be impaired, not improved. A reduced lung diffusion capacity would hinder gas exchange, not aid performance. A lower VO2max signals reduced aerobic capacity, which isn’t an acclimation benefit.

Altitude exposure prompts the body to boost oxygen-carrying capacity by increasing red blood cell mass and haemoglobin concentration. When you’re at high altitude, the lower oxygen availability stimulates the kidneys to release erythropoietin, which drives more red blood cell production. More red blood cells and more haemoglobin mean each millilitre of blood can carry more oxygen, raising arterial oxygen content. On return to sea level, this extra capacity helps deliver more oxygen to working muscles during intense exercise, supporting higher performance, especially in endurance activities.

If haemoglobin were decreased, oxygen transport would be impaired, not improved. A reduced lung diffusion capacity would hinder gas exchange, not aid performance. A lower VO2max signals reduced aerobic capacity, which isn’t an acclimation benefit.