Good amateur/semi-pro sprinter: genes or training?

[dot]

What contributes more?

 

[c_record]

genes. i train and race fulltime, but i cant beat my dad who only rides about once a fortnight on average in a sprint. his muscle type is just completely different.

but after two hours he is stuffed and can barely ride, whilst i just feel like i am warming up and my sprint is still the same speed.