I agree with Jukka Salminen, but one has to remember that this process of adaptation by increasing 2,3 DPG takes time. In the reference he has quoted, it says that the mountaineers were adapted to low Oxygen conditions by keeping them in special chamber, simulating conditions of the mountain peak for 42 days. People living at high altitudes already have higher haemoglobin levels and probably more 2,3 DPG levels. Please go through the abstract of the reference carefully to understand what it conveys.
Jukka Salminen Is the increase in hemoglobin concentration(through over secretion of EPO) and Boher effects the only factors in adapting to aerobic exercise at altitude?