This is a non-commercial randomized controlled trial. 15 patients with COPD and 15 age-matched controls will voluntarily reduce their daily step-count to no more than 1500 steps/day, from a baseline of \> 3500 steps/day.
Before and after 14 days of reduced daily step-count, these 30 participants will undergo measures of appendicular mass, quadriceps strength, exercise tolerance and blood and urinary biomarkers. Quadriceps muscle biopsies will also be taken before and after the 14-day intervention.
15 patients with COPD will be studied 14 days apart but will not undergo the intervention.