Where are the runners?

Doing my thrice-weekly 5 a.m. run in the dark today - as one does - I got to wondering why one hardly ever sees runners who racially originate from, what one may call, the Indian sub-continent. I certainly see a number of 'oriental' types, though they are mainly female - nothing wrong with that, of course. But I suppose the absense of the former is also reflected in their relative scarcity in international athletics. We've all seen on TV the occasional be-turbaned guy in major events like Marathons, but I've yet to see a conspicuously south-Asian runner in reality. Considering the enormous population of the geographical area it's a pity, though one is starting to notice a few more runners in, say, the Olympics - again, nearly always female.
I wonder if the reason for the dearth is cultural (perhaps physical acumen isn't given great priority? - though boxing has opened up in recent years) societal, dietary or some other reason. Whatever the cause I certainly look forward with a degree of optimism to progress and increased representation in the area.