When preparing for an important sports contest, it is recommended to train at high altitude (2-3 km above mean sea level). Prolonged exposure to such conditions leads to:

Answer options

1. Decrease of blood viscosity
2. Decrease of ESR
3. Decrease of pOx, which stimulates erythropoiesis and increases blood oxygen capacity
4. Increase of arteriovenous oxygen difference
5. Improvement of plasma colloid-suspension characteristics