Not 'wanna be' but 'WILL be'.. ... ...  Older sporting types now:  

 Don't just think about what you look like now - and what you are struggling to do in your sports. Think how easy it is to improve on where you are now - that's your achievment and motivation to keep on working on it. Maybe you want endurance and cardio fitness rather than big muscles. Train appropriately. If the opposite - OK again, but get advice. Different aims need different approaches. But celebrate the continuing improvement.  Plenty of examples here!