This study is a randomized controlled trial to determine the safety and efficacy of aerobic exercise for patients who have interstitial lung disease (ILD) uncomplicated by pulmonary hypertension. In an uncontrolled study, we observed more efficient cardiorespiratory function, increased physical work capacity, and improved health-related quality of life following aerobic exercise in this study population. Serious adverse events resulting from aerobic exercise training were not observed and our work to date has established plausibility for the efficacy of aerobic exercise training and its safety for patients with ILD.