Patients with chronic respiratory diseases, hypersecretion (sputum production >30 mL/die), and reduced cough efficiency (Peak Cough Expiratory Flow > 150 and < 300 L*min-1) referred to standard pulmonary rehabilitation (PR) will be included. Study design is a single-blind multicentre randomized trial with consecutive recruitment. Following a preliminary run-in period, group comparison will be made between Intervention group using VAKÜM system (Free Aspire, MPR, Legnano-I) added to the conventional manual ELTGOL technique, and Control group using manual ELTGOL alone over 10 daily sessions.