I do two karate sessions a week and that keeps me fit but it gets harder as I get older and the punches hurt a bit more.
as a kid i played ice hockey. again my knees hated it and lost count how many times i ended up in a+e
I used to belong to a gym - I got a discount rate for the university's own facilities. But I never went, and now I get plenty of exercise walking the dog. It's more enjoyable too.