Exercise reconditioning has long been considered an essential component of the pulmonary rehabilitation regime. To investigate the long-term effects of exercise training on exercise endurance and dyspnea in patients with chronic pulmonary emphysema (CPE), we developed a supervised exercise program using bicycle ergometers. Nineteen patients (mean age: 67) with moderate to severe airflow limitation (average FEV1/FVC, 39.8%) were enrolled in a predominantly outpatient rehabilitation program. After their lactate thresholds were measured by an incremental symptom-limited maximum test, patients engaged in exercise training 15 to 30 minutes per day in an arbitrary frequency and at a work rate at or below their lactate threshold (average: 20.1 w). No significant improvements were observed in resting pulmonary function, blood gas, nutrition, or systemic muscle volume. After long-term exercise training (average period: 33 months; average frequency: 6.5 times per month, individually), the patients demonstrated significantly improved exercise endurance and relief of their dyspnea during exercise. These findings provide a physiologic rationale for long-term exercise training by patients with CPE.