The aim of this randomized controlled trial is to investigate the effects of adding PA monitoring and regular feedback of a pedometer (step counter) to an outpatient pulmonary rehabilitation (PR) program on daily PA levels and health status of patients with COPD.

Patients will be randomized to either receive a PR program with PA monitoring and regular feedback of a pedometer (experimental group [EG]) or a PR program alone (control group [CG]). During the PR program, patients in the EG will receive a pedometer to self-monitor their PA and individualized step-count goals. They will continue to use the pedometers and receive individualized goals for 3 months after the program.

It is expected that, by receiving individualized goals and a simple pedometer to self-monitor their PA during and after a PR program, patients with COPD will become more active and adhere to long-term rehabilitation, thus reducing the overall impact of COPD.

Patients with Chronic Obstructive Pulmonary Disease (COPD) present lower levels of physical activity (PA), which have been associated with increased healthcare utilization and reduced survival. Thus, optimizing PA levels has become one therapeutic priority in COPD management.

Pulmonary rehabilitation (PR) is an effective intervention in reducing symptoms and improving patients' functional status and quality of life. However, its effects in increasing patients' physical activity (PA) levels are limited. Previous research has suggested that PR with continuous PA monitoring with feedback may be a suitable approach to increase and maintain patients' PA levels.

Patients who agree to participate will be randomized to either receive a PR program with PA monitoring and regular feedback of a pedometer (experimental group [EG]) or a PR program alone (control group [CG]). Both PR programs will last 12 weeks and consist of exercise training and psychoeducation sessions. During the PR program, patients in the EG will receive a pedometer to self-monitor their PA and individualized step-count goals. They will continue to use the pedometers and receive individualized goals for 3 months after the program.

The impact of the intervention will be explored using a mixed-methods approach.

Assessments will be conducted in both groups at 4 time points: before, immediately after, 3 and 6 months after the PR program. Physical activity levels, lung function, breathlessness, exercise tolerance, peripheral muscle strength, health-related quality of life and healthcare utilization will be assessed in both groups in these time points.

Descriptive statistics will be used to characterize the sample. To analyze changes in outcome measures, data from the two groups will be compared at each time point.

Patients in the EG will also be invited to attend focus groups after the intervention to assess their perspective about the intervention and their satisfaction with the use of the pedometer.

A sample size calculation using the primary outcome was performed based in a previous pilot study. It was found that 12 patients with COPD would be required in each group to provide 80% power (alpha = 0.05) to detect significant differences between groups. However, as PR programs usually have considerable dropouts (around 30%), 16 patients with COPD were recruited for each group.

Inclusion Criteria:

• clinical diagnosis of COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria
• ≥ 18 years old
• clinical stability for 1 month prior to the study (no hospital admissions or exacerbations)
• able to provide their own informed consent

Exclusion Criteria:

• inability to understand and co-operate
• presence of severe psychiatric conditions
• presence of severe neurologic/ musculoskeletal conditions and/or unstable cardiovascular disease
• participation in regular strenuous exercise (e.g., greater than 10 hours per week of running, swimming, weightlifting or any other similar physical activity) prior to the study