Angiotensin-converting Enzyme (ACE)-Inhibition and Mechanisms of Skeletal Muscle Weakness in Chronic Obstructive Pulmonary Disease (COPD)

Inclusion Criteria: * Adult patient with COPD diagnosed according to GOLD criteria. Exclusion Criteria: * Clinically unstable patients (within one month of exacerbation), those with a permanent pacemaker (which is a contraindication to magnetic stimulation), or significant co-morbidity, patients with an accepted indication for ACE inhibition (left ventricular dysfunction, diabetes) or a contraindication such as renovascular disease; creatinine clearance (estimated) \<50); hypotension; use of anticoagulants (contra-indication to biopsy) or ACE-I or ATII receptor antagonists. * Allergy to ACE-inhibitors. * Pregnancy. Patients will not be enrolled within three months of participation in a pulmonary rehabilitation program.