Background: Up to now it is unclear whether IMT as a routine add-on to PR improves clinical outcome in COPD patients.Method: We underwent a RCT with 555 COPD-patients GOLD-stage 2-4. ØFEV1 = 1.42 l = 46.4% pred., Ø age 57,6 years, 65.1% male. The intervention group (IG; n= 278) provided 7 days/week 21 min. high intensive IMT as routine add-on to a comprehensive 3-week inpatient PR-program. The control group (CG, n = 277) underwent the same intensive PR-program (standard PR) but with a sham IMT of identical duration. There was no difference in the baseline characteristics between the two groups. Primary outcome: maximal inspiratory mouth pressure (PI,max). Secondary outcomes: Vital capacity (VC), forced expiratory and inspiratory volume in 1 second (FEV1, FIV1), 6MWD, Quality of life (SGRQ) and dyspnea (TDI).Results:

First analysis of the subgroup of patients with PI, max £ 6 kPa didn´t show other significant differences.Discussion: Routine IMT as add-on to PR resulted in a significant increase of PI max and FIV1. But there were no additional benefits in other outcomes like QoL, exercise capacity and dyspnea in comparison to the very good short-term effects of the standard PR. Further analysis of our data will focus on subgroups and the long-term effects of the still ongoing 1 year follow-up.