I really only focus on people who try to two-up me. It's silly you're worried about the one-uppers.

But seriously, I've had success just bringing them into the tent with you (if it's not a crazy toxic level or you can't cut them out). If you went on a hike but they went on a harder one...celebrate that you both like hiking! Most people doing that behavior are insecure about themselves, so help them feel secure and they'll not feel the need to do it (hopefully)