look at ronnie, as wiggs said.
the longer guys hold off on going all out, the better they become as pros.
when you see today's kids at 19, juiced to the gills like a few recent new pros or USA failures, you know they aren't going to make that big of strides as pros.
Ronnis and kai might not have been 100% natural as amateurs, but they certainly weren't running gh and insulin and god knows what.