People from Africa origins are, as a whole, slightly stronger and faster for a couple of reasons, one is Allen's Rule. Another is white slaveowners only let mate their strongest slaves. After a couple of generations of that, it increased the average athleticism of slaves. The biggest reason though is the mentality that people have. Black people are poorer as a whole and one way to escape the slums is professional athlete. Black people want it more. I would say it is 99% mentality. Are Asians smarter then whites who are smarter then Mexicans and Blacks?? HELL NO. Gotta get your mind straight and correct habbits down and the difference in intellect between people is miniscule, this is same for natural athleticism though not quite to the same extent as intellect as you still gotta have height and decent proportions. Bruce Lee was one of the weakest kids growing up for example and was a beast before he died just to provide an extreme example.
Now Black people and Mexicans are poorer as a whole then whites. Of course this is ONLY due to the upbringing they have etc and not because whites deserve the better jobs. The government is trying to fix this so Blacks and Mexicans have a slightly easier time getting into good schools and some jobs, they aren't doing enough imo.