The feasibility study will involve mixed methods, this means interviews as well as assessment of treatment with inspiratory muscle training therapy (IMT). There are two pathways within the study depending on whether people want to have inspiratory muscle training. People who accept to have inspiratory muscle training will have assessments before training, after 8 weeks of training and at 6 month follow up in addition to interviews before and after the study (at 6 months). For those who choose not to have the inspiratory muscle training the investigators will offer them an interview so that the investigators can find out more about what might have made the study more appealing or what treatments they would have preferred. The investigators will also ask if they wish to be followed up with baseline assessments for the study period and if the investigators can access health records.

Interviews

Semi-structured interviews lasting approximately an hour will be performed at the beginning of the study with participants who accept the IMT pathway and those who decline IMT until no knew themes are raised. These interviews will be used to provide information on reasons for declining pulmonary rehabilitation, attitudes to exercise, attitudes to IMT, treatment preferences and opinions regarding study design and outcome measures (see Interview Topic guide). The interviews will be taped and transcribed verbatim. A follow up interview with study participants who have received IMT will be conducted at 6 months addressing attitudes to IMT and study design and whether they have decided that they wish to engage with other services (such as pulmonary rehabilitation and smoking cessation).

Inspiratory Muscle Training (IMT) method

Participants will perform 8 weeks of IMT strength training using the Powerbreathe Kinetic device (Powerbreathe). Training will progress to 60% maximum inspiratory pressure (PiMax). This means that each breath in through the device is set at 60% of the maximum force you are able to create when you breathe in rather than at full force. 30 breaths are performed at high velocity (paced initially over a period of 15 minutes to allow recovery between each breath through the device). Once established it is anticipated that each training session should take no more than five minutes. Training is performed twice a day, 5 days per week for the first 8 weeks. Training will be titrated (set to a level suitable for the participant) and supervised weekly for the first 8 weeks by a physiotherapist. After 8 weeks training the participants are advised to continue training unsupervised, twice a day, 3 times per week for a further 18 weeks.

Inclusion Criteria:

• People over the age of 35
• with stable COPD (having had no exacerbation needing antibiotics or steroids in the preceding four weeks) with breathlessness on Medical Research Council (MRC) scale of 3 or above who decline Pulmonary rehabilitation (MRC 3 is defined as "walks slower than contemporaries on level ground because of breathlessness, or has to stop for breath when walking at own pace").

Exclusion Criteria:

• History of spontaneous pneumothorax
• incomplete recovery from a traumatic pneumothorax
• asthma
• known recently perforated eardrum
• unstable angina
• ventricular dysrhythmias
• cerebral event or myocardial infarction within the last two months
• not oral antibiotics or steroids for COPD exacerbation within the last four weeks