"living in different climates, landscapes, etc., may affect people's ability to perform better on certain function. During the course of time, it may show in their genes as well."
That sounds kind of LaMarckian to me. The environment doesn't change the genes; it eliminates from the gene pool individuals unsuited to the environment. So, all of the East Africans who couldn't run long distances got et, leaving mostly distance runners. Theoretically. Of course, as the old saying goes, you don't have to be faster than the lion, you just don't be the slowest East African.
I thought Kenya had a high altitude?
so because of that the inhabitants get by with lower oxygen levels, so when they run theyve been adapted to lower oxygen levels for so long that the increase in oxygen is a plus?
any other correlation studies for people who live in high altitudes and run, or ones inwhich the culture has tradition of racing?
other reasons such as peer emulation could apply as well too. (a Kenya runner from the past becomes famous in his country, so alot of younger Kenyans want to be runners too)