<qa>  At Visit 2, subjects will have a partial set of pulmonary function tests done and completeAt Visit 1, subjects who meet all study inclusion and exclusion criteria, will have a full set of pulmonary function tests PFT done and complete a symptom-limited incremental cycle exercise test. At Visit 2, subjects will have a partial set of pulmonary function tests PFT done and complete a symptom-limited constant load cycle exercise test. On the third and fourth visit subjects will be randomized to treatment with either nebulized saline or nebulized Pulmicort in a double blinded, cross-over design, subsequent to which they will have their PFTs and symptom limited constant load exercise testing done. 