I have a hare-brained theory:
I think that Iowa takes talented but not elite athletes (Chevy Impalas) and coaches/trains them so that they can perform at the top-level of the sport (supe-up the engine, insert elite driver). That Chevy Impala can now drive neck-and-neck with a Formula-1 car due to the toughness and guile of the driver (elite skill set developed under tutelage of Iowa position coaches) as well as the hard work of the pit-crew (Doyle and staff) in ramping up its capabilities. However, ultimately that Chevy Impala was not really meant to go 200 mph, whereas the Formula-1 car was. Thus, the Chevy Impala will break down eventually, and the Formula-1 car has a 10 year career.
The 10 year pros are not just freakishly skilled and freakishly athletic, they are freakishly durable. Hard work is an important part of building that durability, but genetics is probably more important.