A pulmonary exercise test helps evaluate integrated response of heart, lungs and musculoskeletal system to incremental exercise. It involves exercising on either a stationary bike or a treadmill, with the amount of exercise you are asked to do being gradually increased. In most clinical circumstances, cycle ergometry is the preferable mode exercise; however, depending on the reason for the testing a treadmill may be an acceptable alternative. Indications for pulmonary exercise testing include evaluation of exercise tolerance, cardiovascular diseases, respiratory diseases/symptoms, preoperative evaluation, pulmonary rehabilitation and others.