The sport things I am aware of you doing are essentially individual activities - you may do them *with* other people, but the challenges are solo. They are not team-based, and only as competitive as you make them.

Contrast with football or whatever else I generally think of as 'school sports.' I think a lot of people have problems with the competitive thing, and feeling left out or 'not good enough,' and those feelings seem to linger far past school.