What do systematic reviews say?

Exercise endurance Duration of constant work rate exercise test (minutes) · patients with chronic obstructive pulmonary disease

Exercise endurance Duration of constant work rate exercise test on treadmill · patients with chronic obstructive pulmonary disease

Change in 6‐minute walking distance · patients with chronic obstructive pulmonary disease

Dyspnoea during treadmill walking Borg scale at isotime during constant work rate treadmill test Scale ranges from 0 to 10, with lower scores indicating less shortness of breath · patients with chronic obstructive pulmonary disease

Change in dyspnoea score · patients with chronic obstructive pulmonary disease

Health‐related quality of life (Change in CRQ Dyspnoea) CRQ · patients with chronic obstructive pulmonary disease