In chronic obstructive pulmonary disease (COPD), the benefits of pulmonary rehabilitation (PR), which are: an improvement of exercise capacity, symptoms, and health-related quality of life tend to wane over time.  The objective of this study was to determine whether a long-term (3 years) supervised maintenance program after PR preserves the short-term effects on the outcomes in patients with moderate to severe COPD compared to minimal standard monitoring programs. Some other studies have shown that the benefits of PR programs last no more than 1 year with a maintenance technique, whereas other studies have shown that these techniques manage to extend the benefits of PR for longer periods.