The body uses several proteins to deal with conditions of low oxygen, one of them is HIF1a (coded by the HIF1a gene). HIF1a controls the activation of genes affecting glucose processing, metabolism, and the formation of red blood cells and blood vessels. One variant of this gene was found more frequently in weightlifters, while the other was found more frequently in elite endurance athletes and was associated with a higher increase in VO2 max through aerobic exercise training.
Global population distribution:
Source: 1000 Genome Project. Global averages for both sexes
More about HIF1A
HIF1A AND THE ENVIRONMENT
HIF1A stands for the transcription factor Hypoxia Inducible Factor 1A, and like its name says (hypo=low, oxia=oxygen), it responds to situations of low oxygen, for example when you are in the mountains. At high altitudes the atmospheric pressure and thus the partial pressure of oxygen are lower than at sea level (4000m vs sea level: atmospheric pressure 63kPa vs 101kPa, partial oxygen pressure 13.3kPa versus 5.6kPa). This makes it harder for the body to absorb oxygen and initially results in low oxygen levels of the blood (hypoxia). The body responses to this, amongst other mechanisms, via HIF1A. Whilst at sea level HIF1A is rapidly degraded, but at high altitudes HIF1A is preserved and helps the body adapt by improving the efficiency of oxygen delivery to cells.