Effect of Rehabilitation at Moderate Altitude on Airway Resistance Measured With Forced Oscillation Technique in COPD-patients

This study looks at how a rehabilitation program at moderate altitude (about 1,500–2,000 meters above sea level) affects airway resistance and breathing in people with COPD (chronic obstructive pulmonary disease — a long-term lung condition causing breathing difficulties). **You may be eligible if...** - You are 18 years or older - Your COPD has been stable for more than 3 weeks (no recent flare-ups) - Your resting blood oxygen level is at least 88% on a pulse oximeter - Your oxygen levels drop significantly during a 6-minute walk test - You are willing and able to provide informed consent **You may NOT be eligible if...** - Your oxygen levels are dangerously low at rest (below 88%) - You are on continuous oxygen therapy - You have an unstable condition requiring medication changes or intensive care - You have a condition that prevents you from walking or cycling (e.g., serious orthopedic or neurological problems) - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.