Take notice when he limps, or lands funny, and stop the session immediately. Your dog will play frisbee with 4 broken legs, it is up to you to be sensible when you see he has over-exerted himself. No matter what, keep it fun. The whole thing started with you and your pup having fun and exercising in the fresh air. Never lose that perspective.
Dogs are very different from cats in that they can be images of human virtue.
They are like us. Try using the search in the top right.