Most of what you "keep hearing" is nonsense with no scientific basis. All "racial" explanations of athletic performance should be treated with tremendous skepticism, and not just because there is a long and unhappy history of social and institutional misuse of such theories - also because there is not much science supporting them. The very notion of "race" in the human population is not well defined at all - skin color is about as meaningful, in a genetic sense, as is eye color or hair color. One should speak of the genes controlling skin pigmentation, rather than skin color, although there is more to it.User Guide said:Why dosent Nigeria dominate sprints and the like?
Keep hearing about fast twitch muscles and west african body shape (lower centre of gravity etc) surely a country with such a large population should be producing more world class sprinters.40-50 times as many people as Jamaica.
Although anecdotes prove nothing, I'll give the example of a child I know - he is the spitting image of his father in every single way except for one minor detail - the father is "white" (on any continent) and the son is "black" (on any continent). Obviously they are closely related genetically. In a scientific context, race in the colloquial sense is not a useful surrogate for genetic identifiers, and genetic and cultural variation do not correspond in sharp way with genetic variation.
Many of the sprinters that in the US are considered "black" would be regarded as "white" in much of Africa. There's no genetic marker that corresponds to "black" and "white", and a place like Nigeria is very diverse ethnically, so saying something like "west african body shape" makes no sense at all. The short-statured "pygmy" populations in parts of Africa are genetically distinguished from the rest of the human population - although how to characterize the distinction in genetic terms is still not well understood. This is just to say that there are definitely human subpopulations with identifiable genetic differences from other subpopulations. However, note that the Pygmy populations live among other populations which, while distinguished genetically, would also be considered "black" by unscientific racial categorizations.
Why are there so many Spanish cyclists and so few Spanish sprinters and so few Jamaican cyclists and so many Jamaican sprinters? It is not because doping is better in Spain than in Jamaica, nor is it because Spaniards are "white" and Jamaicans are "black" (two plainly ridiculous statements). It has more to with Spain being mountainous and dry and Jamaica being an island in the Caribbean, and other social/cultural factors (e.g. the availability to Jamaicans of US track and field programs and the long European tradition of cycling races) than to pseudo-scientific claims about preponderance of "fast twitch" muscles. Cycling sprinters must need fast twitch - they are almost all "white". Anyone who speaks of Ethiopians, Kenyans, Jamaicans, and Nigerians as all members of one homogeneous "black" racial group is just talking nonsense.