It is not PC to point out that there are real genetic differences between the sub groups of our race. I pulled this quickly off another post - not my words -
link to a decent explaination on fast twitch/slow twitch -
http://www.jonentine.com/reviews/AAAS_peeringUnderTheHood.htm
In his book "Taboo: Why Black Athletes Dominate Sports and Why We're Afraid to Talk About It", Jon Entine interviewed scientists who have done research into elite athletes.
The scientists said that people from different parts of the world have differences in their DNA that affect more than skin color. Your muscles are a mixture of fast twitch fibers and slow twitch fibers. Sprinting speed comes from fast twitch, and endurance from slow twitch.
Entine said it has been shown, using the list of Olympic track and field medalists, that a different area of the world produces the best athletes in each event. Not the country of citizenship, but where their ancestors came from. Sprint medalists are from the Caribbean. Distance medalists are from one part of Kenya.
Is it wrong to talk about it? Only if you are a leftist. The scientists in Entine's book have already been insulted by their leftist academic peers for daring to study anything connected with race. Some feel they can't publish their scientific results in academic journals for fear of reprisal. Leftists don't tolerate scientific proof. Leftists believe freedom of speech only applies to themselves.