It is unknown whether individuals with COPD exhibit abnormal alveolar-capillary breaching during exercise, and whether this contributes to exertional dyspnoea. The aim of this study is to investigate whether individuals with COPD exhibit an abnormal increase in alveolar-capillary breaching during exertion, as indicated by an increase alveolar-capillary permeability with a concomitantly exacerbated increase in lung tissue mass. The study participants include a control group and a group with COPD (GOLD I-III). Participants are undergoing three study days: (1) Measurement of maximal aerobic capacity and lung function test, (2) lung tissue mass and alveolar-capillary permeability is measured at rest and again 2 hours later, immediately after the participant has exercised on a bicycle ergometer and (3) supine cardiac output and pulmonary capillary blood volume will be measured at rest and immediately after exercise.
