Developing Personalised Relative Physical Activity Thresholds in COPD.

Physical activity (PA) helps prevent and manage non-communicable diseases such as chronic obstructive pulmonary disease (COPD). Pulmonary rehabilitation (PR) has been shown to benefit people living with COPD by reducing breathlessness, increasing muscle strength, and improving the management of exacerbations. However, the improvement in PA in individuals with COPD remains inconsistent following PR. Despite the personalised nature of PA prescription during PR, the evaluation of free-living PA data has been limited to a 'one size fits all' approach using absolute intensity categories. Reduced exercise tolerance can result in PA being perceived at a high intensity relative to a person's exercise capacity, despite the absolute intensity being low. Exploring both the relative and absolute intensity of PA could offer additional insights and clinical relevance for the evaluation of physical activity in COPD populations. The aim of this research is to translate the principle of individualised exercise prescription into the evaluation of daily absolute and relative intensity PA in a user-friendly format for PR teams and service users. Phase 1 objective: To explore what PA means to people with COPD in the context of relative intensity and pulmonary rehabilitation. Phase 2 objective: To examine the differences between time spent in physical activity intensity expressed in absolute and relative terms for people with COPD. Phase 1: Semi-structured interviews will take place where participants will discuss their COPD and their perceptions of physical activity and relative intensity. The interviews will be in person (Biomedical research centre, Leicester) or over the phone/video call. The participants will complete several questionnaires about respiratory symptoms. Before taking part in the interviews, participants will also be asked to take pictures, using a camera provided, of when they are doing physical activity. This will be for a 7 day period before the interview. Phase 2: Participants will take part in exercise testing and complete questionnaires pre and post pulmonary rehabilitation while wearing activity and gait monitors. Participants will also be asked to wear the activity monitors for 8-days after the pre-testing sessions and 8-days after their last pulmonary rehabilitation class. Following their last pulmonary rehabilitation class, 20 participants will be asked to take photographs during the period they are wearing accelerometers and motion sensors. When the participants return the devices, they will take part in an interview to discuss the images they have taken while taking part in physical activity.