I have no hesitation in saying that the format of my gym training was the single biggest factor in winning back-to-back World Championships in 2009 and 2010.
"A gym program first approach formed the basis of my endurance training, not the other way around"
What amazes me, after all my years experience in fitness and triathlon is the lack of programming uptake in triathlon circles. I have not witnessed many effective progressive programs in endurance sports in general. With regular programs there are often 'sessions' with a focus on a specific fitness component without structured progression, I find this diluting and confusing. It's all over the place and difficult to pick-up where you left off. Imagine how your body feels!?