I think the problem with it is that it sounds like something that was formulated down the pub. There is zero scientific evidence behind it afaik.
And most anyone of African orgin on the western side of the Greenwich meridian is likely to be of slave descent. The idea that their athletic achievements are down to massa ranges from naive to problematic.
Also, I don't think slave traders held tryouts. They were a little more indiscriminate than that.
Watched the documentary a few weeks ago, there was some science to it alright. Slave traders were indiscriminate but most died on the way over. African Americans who survived the slave ships apparently did so on fuck all water so those who metabolised salt more slowly (I think) stood a better chance of survival. 100 years later and this genetic trait makes them more suseptable to heart problems. There's another genetic theory about diabetes. So it's not all one sided, black men are super human nonsense. The strongest made it through argument seemed fairly cogent to be honest.
Why is it we only ever stand a chance of winning a medal at fighting. Is it because boxing is an integral part of GAA and the GAA have all out best athletes?
Ah now in fairness per capita we over achieved at football for years.
http://footballtoptens.wordpress.com/2010/09/08/top-ten-small-international-teams/