Endurance training in COPD improves exercise capacity, and high intensity training may have greater physiologic benefits than lower-intensity exercises. Dyspnea and fatigue often limit patients with severe COPD from high-intensity exercises. This randomized trial compared 30 severe COPD patients awaiting lung transplantation assigned to high intensity interval training to 30 patients assigned to lower-impact continuous training. Interval training was associated with lower intensity of dyspnea during exercise and fewer unplanned breaks. Changes in lung function parameters were not significantly different between the two groups. Both groups had improvements in 6-minute walk distance.