Pulmonary bullae can not exercise vigorously, which may lead to spontaneous pneumothorax. It is necessary to insist on oxygen inhalation and rest quietly to avoid strenuous exercise and infection. If you feel chest tightness and discomfort, see a doctor in time.
Dyspnea after exercise is related to pulmonary dysfunction caused by your pulmonary bullae. If the bullae are very large or many of them are confined to one lobe, surgery can be considered.
I suggest you show your film data to the chest surgeon to see if you can perform surgery. If you want to improve lung function, you need to remove useless pulmonary bullae. It is impossible to improve your lung function with exercise, and strenuous exercise will only aggravate your breathing difficulties because of your poor lung function, so you should consider your exercise amount appropriately according to your physical condition.
It is a principle that patients should not do strenuous exercise. Although exercise can better ensure our health and achieve the best effect of preventing some diseases, if it is really not allowed by their physical condition, then they need to pay attention to these principles and not cause more adverse effects on their bodies because of exercise.