Black Athletes Should Thank Slavery, Suggests BBC

In the short film below, the BBC suggest that the reason black athletes are so successful in sprint races is due to slavery.  Only the strongest survive slavery, say the BBC, and so the descendents of slaves are naturally fitter and stronger than those who did not have slavery as a beneficial birthing pool for their genes.  I do trust I am not alone in being utterly nauseated by this offensive and patently ridiculous suggestion.