I think you could totally start gymnastics at 13. I mean you might not go to the Olympics or anything, but I'm sure you could get pretty good. I don't actually do gymnastics anymore because I took up tennis, kickboxing, badminton, and soccer. hah. yeah and I played JV on badminton my first year ever playing (Which btw they tried to get me to play varsity), and varsity for tennis after like 3 years of playing. BASICALLY as long as gymnastics is something that you really like and you want to do because you really enjoy it, then I'm sure that you could excel and possibly even catch up to others who have started gymnastics wayyy before you. :]] HAVE FUNN!!!