Patients were assigned to inspiratory muscle training (IMT) for 6 weeks. During training, patients were instructed to maintain diaphragmatic breathing, and try to maintain 10-15 breaths, and rested 5-10 between breaths. As soon as the patients managed; they were encouraged to maintain 25-30 breaths at each workload. All patients wore nose-clip during training. The inspiratory load was set at 40% of maximal inspiratory pressure. The training session was supervised at the hospital.

Patients received IMT for 30-minute per day, 3 days per week for 3 weeks using the Threshold Inspiratory Muscle training device (product Phillips). During training, patients were instructed to maintain diaphragmatic breathing, and try to maintain 10-15 breaths, and rested 5-10 between breaths. As soon as the patients managed; they were encouraged to maintain 25-30 breaths at each workload. All patients wore nose-clip during training.

Inspiratory muscle training diaries were checked weekly. The inspiratory load was set at 40%of maximal inspiratory pressure.

Six-minute walk test (6MWT) was applied in a 30-m unobstructed corridor. Patients and controls were instructed to walk at their own pace but to cover as much meter as possible within 6 min. Each minute standardized encouragement was given to the patients. Patients were allowed to stop and rest during the test but were instructed to go on walking as soon as they were able to do so. Heart rate and spo2 were monitored using pulse oximetry before and ending the test. Maximum heart rate values achieved during the tests were recorded. The rate of the perceived exertional scale was used before and after the 6MWT. The 6MWT distance is expressed as a percentage of the predicted values.

Measurements of forced vital capacity and forced expiratory volume in 1, forced expiratory volume in one second/forced vital capacity, peak expiratory pressure was obtained with a computerized spiro-lab device as recommended by the European respiratory society, and results were expressed as a percentage of predicted values.

Quality of life was assessed using SF-36. The SF-36 is a generic measure, consisting of eight

subscales and 36 items. These subscales are physical functioning, role-physical, role- emotional, mental health, social functioning, bodily pain, general health. All subscales range

from 0 (worst possible) to100 points (best health).