In this randomised, crossover trial, 22 patients with severe chronic obstructive pulmonary disease climbed six flights of stairs (108 steps) twice, under two test conditions: (1) energy conservation technique (ECT): participants were asked to rest for at least 5 seconds every three steps and (2) control condition: participants climbed the stairs at their own pace. Significant lower dyspnoea (primary outcome), leg discomfort, minute ventilation and capillary blood lactate under the ECT condition were found, with no change in total task time.Clinical trial registrationNCT03564028