Fat does not equal out of shape and thin doesn't equal in shape. I know plenty of big dudes That keep up or out perform little dudes in multiple sports. I'm 6' 290 an can board all day. I play basketball with little duded an keep up. I lift weights and out lift most of my friends. I also don't Do many jumps but I would have when I WAs younger. I'm 33 now.
Man I'm not calling you out so don't take it that way, but come on, lol, don't let being 33 keep you from the kickers, I'm 32 and ride park almost all day. Never too old!
Edit: As far as the topic goes, flexibility can play a large part in things too.