Work field my daughter is not even close to reaching. But, sports she is! And what I hear and know no matter what exercise is the best thing ya can do! working out the lungs and moving the gunk out. Even if it on a dust baseball field . The work out will counter act the dusty environment. Basically if the activity out weighs the potential hazards of P.C.D life such as a dusty field your doing pretty well. Swimming is the best activity for a P.C.Der pure aerobics and mist of water!