Home-based Body Weight Exercise With Blood Flow Restriction (BFR): Feasibility of a Novel Rehabilitation Intervention in COPD Patients (HomeBFR-COPD)

Experimental design: This is a randomised, controlled, assessor blind, single centre, clinical trial. Outcome measurements will be assessed at baseline and following the 6-week home-based intervention. Participants: 40 Eligible participants will be identified and approached by their own clinical team at routine clinical appointments or at the point of referral to pulmonary rehabilitation (PR). In addition, potential participants who didn't attend PR or are on the waiting list and individuals who have previously provided written consent to be contacted about future research studies will be contacted via post. If interested, a researcher will explain the study and provide the Participant Information Sheet. All participants will be given at least 48 hours to consider taking part and written informed consent will be obtained before any study procedure. Experimental protocol: Patients will be randomised (1:1 intervention: control ratio) matched for age and lung function to a home-based body weight exercise intervention including sitting knee extensions, standing knee raise, heel-toe raises, bilateral mini-squat behind a chair, and chair rise/sit to stand either with or without the blood flow restriction (n=20 in each group). Baseline outcome measures will be conducted over the first visits to the clinic. Initial two training sessions will be directly supervised in the research centre (visits 2 \& 3) to ensure all exercises are performed correctly and safely and the patient become familiar with the trial equipment and related mobile application for exercise guidance and session recording (digital training). During both sessions, physiological measurements will be made frequently venous blood samples to assess markers of inflammation, immune and vascular health will be obtained. A brief survey to assess exercise experience will e completed at the end of visit 3. Patients will then be asked to carry on by performing the same exercises three times per week at home for the next five weeks. The programme will start at a quite easy level and gradually increase in intensity every two weeks depending on how the participant gets on. Progression will incorporate an increase in the number of repetitions and sets every two weeks. After the intervention phase, patients will return to the research centre for post-intervention assessment visit (visit 4) where post-intervention outcome measures (including a post-training resting blood sample) will be conducted over the same time-course as the baseline measures. at the end of the visit, a brief survey to assess exercise experience will be completed. In addition, half of the participants will be interviewed, within four weeks of completion of the study, to qualitatively assess perceived expectations, benefits, motives, and barriers to the intervention.