The physical advantage [race based superiority] for running and jumping is obvious.
They also have greater quantities of the "Warrior Gene".....MAOA...which makes them genetically predisposed to chimping out.
Their kids live a tougher life, with more abusive parents and the kids find themselves out in the streets scrapping over everything.
By the time the typical Inner City Black Kid is ready for Middle School he/she has already been in more fist fights than 10 White People will ever get into during their entire lifetimes.
If you want to see young kids still playing Pop Warner Football, or enrolled in after school boxing and martial arts....visit your nearest Majority Black Neighborhood
These "Inner City Youf" Physical Training Programs are funded primarily by White People...right?
while the White Kids spend their childhoods indoors playing nintendo ..totally afraid to go outside where the rough Negro kids are playing basketball until mid night.