Oxygen may improve exercise tolerance by increasing arterial oxygen
content thereby directly inhibiting carotid body stimulation,
improving muscle oxygenation, allowing reduction of lactic acid
production (thus decreasing carotid body stimulation) and causing
pulmonary vasodilation, leading to increased cardiac output
and muscle oxygen delivery (Fujimoto 2002; Somfay 2002). The
combination of exercise training and supplemental oxygenmay interrupt
the downward spiral by enabling individuals with COPD to tolerate higher levels of activity with less exertional symptoms,
ultimately improving quality of life.