From certain regions genetically, but you have made the "unconscious bias" mistake of lumping all black people together in terms of their physique which varies massively.
We are all guilty of it. We tend to think that black people are better at the 100 metres, but wouldn't think that white people are better at rock climbing.
We note that the hundred metres final is "filled" with black contestants but don't think about other sports that on reflection are mostly contested by white people.
Running is the only sport in the world where accessibility is even for everyone (except a few weird people living on the top of steep mountaints etc), which is what makes the genetical thing interesting. The best short-distance runners are from Western Africa and the best long distance runners are from Eastern Africa. Both with a few expections of course.
That's why it is remarkable and often mentioned: everyone can run but people with African heritage are better at it.
Sports where white people dominate are in various degrees mainly accessible for white people. No one finds it interesting or fascinating that white people win all bobsleigh competitons when 99% of the people who can afford and access it are white.
Sometimes in discussions about this, people bring up swimming. "There's water everywhere so everyone have the same access etc", which is a very eurocentric perspective and flawed at that; any healthy person are able to run naturally, while it actually takes teaching to learn swimming. In countries like yours and mine 80-90% are able to swim, over at Donaldland its about 50% or so (bit more maybe) while in many Asian and African countries very, very few got that swimming education that is easy for us to take for granted.
To learn how to swim professionally its also a big fat advantage if you have the facilities for it and a lot of countries dont have a single 50m pool to train in.
Running and jumping are the sports where black & white people have the same opportunity to compete, and these sports are generally dominated by black people. Sure, that hurts in both the racist and the anti-racist just like females being unable to compete with men in any physical sport hurts the feminist, but thats how it is. The world is unfair.