Agreed - Also learn how your body responds and recovers as much as possible. Keep an eye on your nutrition also. It makes the changes later much easier. I'm 35, and there's definitely major changes in the way my body responds, recovers, etc. That said, I'm still competiting at the same level I was in my mid - late 20's, if not a little higher (not that I was ever a pro or anything, but my #'s are still going up, at least). Stay as consistent as humanly possible also.