Introduction

Athletes often train at high altitudes to enhance their physical performance. The key physiological adaptation induced by these conditions revolves around improved oxygen delivery to muscles. Understanding this mechanism clarifies why training in low-oxygen environments benefits endurance and athletic output.

Main Reason Athletes Train at High Altitudes

(1) To increase the number of RBC (Red Blood Cells)

• High altitudes have lower atmospheric pressure, resulting in reduced oxygen availability in the air.

• As a response to hypoxia (low oxygen), the body produces more erythropoietin (EPO), a hormone that stimulates the bone marrow to generate more red blood cells.

• Increased RBC count enhances the oxygen-carrying capacity of the blood.

• More oxygen delivery means muscles can perform more efficiently during exertion, delaying fatigue and improving endurance.

Additional Physiological Benefits of High-Altitude Training

• Enhanced VO2 max: Maximum oxygen uptake during intense exercise increases, allowing better aerobic capacity.

• Increased capillarity and mitochondrial density: Improving oxygen exchange and utilization in muscle cells.

• Improved lactic acid tolerance: Higher altitude training increases the threshold at which muscles accumulate lactic acid, enhancing tolerance to fatigue.

• Better lung function and oxygen uptake: Over time, there can be an increase in lung capacity and efficiency.

Why Other Options Are Less Relevant

• (2) To form modified hemoglobin:
  Although certain animals have adapted hemoglobin variants for high altitude, in humans, the primary adaptation is increased RBC concentration rather than hemoglobin modification.

• (3) To increase number of WBC:
  White blood cell count is not significantly affected by altitude training for athletic performance.

• (4) To increase amount of globulin proteins:
  Globulin proteins are unrelated to oxygen transport or endurance capacity improvements.

Summary Table

Conclusion

Athletes train at high altitudes mainly to:

Increase the number of red blood cells (RBC) to improve oxygen delivery and endurance.

Answer: (1) To increase the number of RBC