Oh I see!  And swimming is also useful for survival, right?
That would be a much better activity for someone with lung disease than other recreations, sports, or exercises
I love to swim and it keeps me in shape Nice!  It's a good "low-impact" sport, compared to running. Yes and I have lung disease its very easy for me to exercise in water, much easier than a gym workout
Swimming is the self-propulsion of a person through fresh or salt water, usually for recreation, sport, exercise, or survival.