Razib has a fun, speculative post about the Great Brown Hope -- looking for reasons why South Asians are underrepresented in sports.   

He starts with:

I've been involved in an e-mail correspondence with another fellow South Asian on the lack of athletes from my ancestral region. He pointed out the pathetic medal count from India, Pakistan and Bangladesh in proportion to their population at the recent Asian Games.

Is there a possible genetic factor in this?

He has a good survey of suspected issues (public health standards, vegitarianism, Caste, etc.)