There are special training programs for professional bike fitters. Is the one you're going to professionally trained, or just some dude who adjusts stuff at the shop? I got a fit by a trained fitter and it's been the best money I spent on the bike. I didn't have any injuries, but from all of the little adjustments he made, and some larger ones (new handle bars and stem) I noticed a HUGE difference in comfort and my ability to ride longer distances.