I can see why you still hold this position about this topic over the course of your whole life because you aren't taking it seriously. This despite the fact that it doesn't pass the sniff test, and has been used historically for evil.
First of all yes, actually, people in poor places in East Africa, often more rural, do see long distance running as a pathway to success if they have interest and ability, and because of all sorts of success there, that ability is harnessed and trained. I'm not sure why you are being facetious about that.
Yes, certain peoples can have some genetic advantages, which they can exploit if they also have a pathway to success and the infrastructure that goes with it. Those people aren't "black". There are specific genetically similar peoples in specific parts of East Africa who may have some advantages for a very specific athletic pursuit. You've begun making a much, much more narrow claim here, that still isn't quite supportable due to lack of specificity.
It's like saying that white people are stronger because Icelandic people might be. That's the depth of your original claim.