Background <p>The use of behaviour change techniques to promote physical activity and reduce sedentary behaviour in individuals with chronic obstructive pulmonary disease (COPD) has been the focus of recent research. However, previous studies have not explored such techniques embedded in physical training (PT) to improve the physical activity levels and reduce sedentary behaviour in this population. Therefore, this study aims to describe a PT protocol incorporating behaviour change techniques based on the Self-Determination Theory to enhance exercise motivation and level of physical activity in individuals with COPD.</p> Methods <p>This descriptive protocol for a randomized, double-blind clinical trial will recruit individuals with stable COPD. Individuals will be randomized into intervention and control groups, both undergoing individually prescribed PT for 12&#xa0;weeks. Only the intervention group will perform behaviour change techniques based on the self-determination theory during PT sessions. The groups will be reassessed at the end of the protocol and 6&#xa0;months after the intervention. Primary outcomes will include level of physical activity and sedentary behaviour, assessed by using the ActivPAL3™ triaxial accelerometer (PAL Technologies Ltd., Glasgow, UK) for at least 4&#xa0;days for 8&#xa0;h daily.</p> Discussion <p>The intervention protocol is expected to improve exercise motivation and level of physical activity of individuals with COPD. Also, this protocol may promote behaviour change in this population and be adapted for clinical practice.</p> Trial registration <p>Brazilian Clinical Trials Registry (ReBEC): RBR-9ykz7ws. UTN code U1111-1305–4463. Registered on August 9, 2024.</p>