If you can and your doctor has not told you otherwise, do what you can to move, i.e. bike, walk, do steps, anything aerobic within your abilities that also gets you coughing up the mucus. The mucus sitting in your lungs could be damaging you more— getting it out is important, at least it was for me. My doctors have told me that my exercise has kept the disease from damaging me more than it would have if I did not exercise. I asked them why no one ever told me to exercise and they said they stopped doing it because no one listened.