Twenty-one patients with severe chronic irreversible airflow obstruction (FEV1 consistently less than 1.2 l) were allocated randomly to one of two training programmes designed to reduce respiratory disability or a placebo training control group. Daily structured physical exercise, twice daily inspiratory muscle training by resistive breathing, or daily placebo training were undertaken for 10 weeks, and the effects on lung function, exercise capacity, respiratory symptoms and psychological state compared. Maximal work achieved on a progressive bicycle exercise test was significantly increased in all groups (36%, 23% and 34% respectively) and global improvement in mood also occurred. There was no significant change in respiratory symptom score, static lung function tests or 12 min walking distance. Neither form of active treatment showed superiority over placebo training.