In order to evaluate the possible effects of respiratory muscle training in patients with neuromuscular disease, we trained a group of 12 patients and 6 normal subjects for 8 weeks with 4 weeks of strength training and 4 weeks of endurance training of the respiratory muscles. We measured static and dynamic lung volumes and maximal expiratory flows in a whole-body plethysmograph and endurance in an original set-up. The main finding was a significant rise in vital capacity and respiratory muscle endurance in the patient group; therefore, daily specific training of the respiratory muscles can improve strength and endurance in patients with neuromuscular diseases as well as in normal subjects.