You'll find most of the same exercises in my forthcoming TUFFCUFF manual. Most of the Cubs pitchers performed the same -- or very similiar -- routines. Of course not everyone looked like Kyle. But not everyone had the same work ethic in the weight room as he did either.
He was a "gym hound" -- and I mean that in a good way. He worked hard, payed very close attention to his diet, and was blessed with good genetics.
Interestingly enough, the fastball came much later in his development. Out of high school, when he was drafted by the Cubs, he was a mid-80s mph guy. Tall and skinny. The 97-plus stuff only started happening when he got to high-A and double-AA.
His former teammates, some of whom were my coaches in pro ball, credit his velocity to his physically filling out as he got older, his increased strength (he's really flexible, too, by the way) and his pitching mechanics.