Bradley B L, Garner A E, Billiu D, Mestas J M, Forman J
Am Rev Respir Dis. 1978 Aug;118(2):239-43. doi: 10.1164/arrd.1978.118.2.239.
Twenty-six patients with severe chronic obstructive lung disease exercised on a treadmill while breathing either room air, supplementary compressed air, or O2. Endurance was significantly increased by O2, but there was no improvement in maximal work rate. No relation was found between increased endurance and the degree of hypoxia, hypercarbia, or acidosis during exercise or the changes in these while breathing O2.
