Performance difference on the six-minute walk test on tracks of 20 and 30 meters for patients with chronic obstructive pulmonary disease: validity and reliability

The objective was to compare the performance between the 6MWT on a 30- (6MWT30) and 20-meter (6MWT20) track; to evaluate the validity and reliability of the 6MWT30 and the 6MWT20; and to determine for which patients track length has the greatest impact on performance.