People with COPD could derive substantial health benefits by increasing PA, but exercise training and pulmo¬nary rehabilitation have been unsuccessful in addressing the problem. Pulmonary rehabilitation is widely used, and is effective in increasing exercise capacity and health-related quality of life, but for the most part it has not been effective in increasing PA, possibly because it does not adequately address the behavioral issues associated with many years of habitual inactivity. While many pulmonary rehabilitation programs include health education and the benefits of PA, few have employed theory-based behavioral interventions to change PA behavior.