The Aim of the Study is to Decipher the Alterations in Signalling Pathways of Skeletal Muscle Stem Cells (Satellite Cells (SCs)) in Individuals With COPD, as Well as to Examine the Effect of Exercise Training on SCs.

The aim of the study is to decipher the alterations in signalling pathways of skeletal muscle stem cells (satellite cells (SCs)) in individuals with COPD, as well as to examine the effect of exercise training on SCs. To this end, the team will perform an exhaustive evaluation of lung and muscle function, including exercise capacity, as well as muscle biopsies, before and after a 2-months rehabilitation program. This study should provide new therapeutic avenues for COPD-associated sarcopenia.

Inclusion Criteria: * Adult male or female (age 18 years or older); * Having a diagnosis of COPD according to the GOLD (Global Initiative for Lung Disease) 2024 criteria, i.e. a non-reversible bronchial obstruction in spirometry with a post-bronchodilator Tiffeneau coefficient \< 70%; * Less than or equal to 75 years of age; * Must benefit from exercise retraining sessions or respiratory rehabilitation as part of the management of COPD; * Person affiliated to or beneficiary of a social security scheme (excluding State Medical Aid (AME)); * Free, informed and written consent signed by the participant or by a third party (in the event of the participant's physical disability) and the investigator (no later than the day of inclusion and before any review required by the research). Exclusion Criteria: * Moderate or severe acute exacerbation of COPD, or acute intercurrent condition (e.g., infection) that has been ongoing or resolved for less than 4 weeks; * Systemic corticosteroid therapy in progress or stopped for less than 4 weeks; * Contraindication to respiratory rehabilitation: tight aortic stenosis, unstable heart failure, active thromboembolic disease, ventricular aneurysm, uncontrolled arrhythmias; * Contraindication to muscle biopsy: acquired or innate haemostasis disorders, anticoagulant treatment or double anti-platelet aggregation; contraindication to lidocaine: known hypersensitivity, patients with recurrent porphyrias; * Presence of a concomitant muscle pathology, innate (e.g., genetic myopathy) or acquired (e.g., myositis, progressive cancer); * Pregnant or breastfeeding woman; * Patient under guardianship or curatorship; * Refusal to participate in the study. Exclusion criteria: \- Hemostasis disorders.