River City Girl,   Thanks for your question.   I think you are on the right track with your rationale and efforts so far.  However, for safety, I suggest you consult with your physician before embarking on an exercise program that includes cardio.  I am concerned about your heart, which can be affected by your lung disease.  I want to be sure that the exercise program is safe from a cardiac point of view and therefore the checkup with the doctor is needed.  I suggest you discuss the need for a stress test.  If clearance is obtained, then consider a consultation with an exercise physiologist to prescribe a program that is tailored to your health situation and needs.   Best wishes.   Martin Cane, M.D.