I am sorry, but you are wrong. There is plenty of reputable scientific evidence. It has to do with the type of muscle fibres and their slow/fast twitch response. They are different in black people to that of a white person.
It basically means means that black peoples muscle fibres lead towards building explosive strength. Which is why basketball/athletics is generally dominated by black athletes.
Yep more red blood cells IIRC....which I probably don't but there is definitely a difference.