What is a typical physiological adaptation to exercising at altitude above 7,874 feet?

• A. Increase in red blood cell count and oxygen transport
• B. Decrease breathing rate
• C. Decrease in red blood cell count
• D. No change in physiology

Answer: (A)

Exercising at high altitude presents less available oxygen, so the body adapts by boosting its oxygen-carrying capacity. The main response is an increase in red blood cell production driven by erythropoietin, which raises hematocrit and hemoglobin levels and improves how oxygen is transported to tissues. This acclimatization unfolds over days to weeks and is a common way the body counteracts hypoxia at elevation. Breathing rate actually tends to rise to enhance oxygen intake, not decrease, and a reduction in red blood cells would impair oxygen delivery, while no change would leave tissues inadequately oxygenated. So the best answer reflects more red blood cells and better oxygen transport.