The correct answer to this one question is the following.
Unfortunately, you did not attach the documentary or a link to it.
However, we can comment on the following.
There is an expert on this topic named Joseph Graves Jr. He is a professor of evolutionary biology who teaches classes at Emory-Riddle University. He has researched the subject of race and physical abilities. Among those studies is "Biological Theories of Race at the Millenium."
According to Professor Graves, I think that some groups seem to dominate certain sports more so than others because they have the biological characteristics that predispose them to perform better in athletics.
That is the case with black people. They clearly have the physical size and speed to be wonderful athletes in specific sports such as football and basketball. It is impressive the athletic capacity and faculties these black people have to outperform other races in these sports.
So professor Graves states that this has to do with some genetic predisposition but also with the environment they grew up in, which includes the kind of strength and conditioning programs they participate in, nutrition, coaching, and mental preparation to perform at the highest levels of professional sports.
