I suspect that there will be good swimmers around the world who are black. That in fact that race is a way that society divides it people. Nonetheless there are genetic differences between humans, but these are equal amongst White people, Blacks and Asians. I think he's got that spot on. The predominant wisdom now in mainstream science, endorsed by someone like Professor Steve Jones who was on the programme, has said there is no useful concept such as race in science.
Race is a social concept.
We are, in the Western Hemisphere, divided into black and white because of history, for no other reason. That's probably true. What can also be said is that in societies where the opportunities are limited and there are areas where there are perceived to be an opportunity for success, people will gravitate towards that. That's irrespective of skin colour. It just so happens that black people, black youngsters, have seen success in sport, throughout the United States, throughout Britain, and therefore they aspire to it.