It is still not clearly known whether doing the walk test in a course is different from doing it on a treadmill in the lack of a ten-meter-long corridor. In case of a positive outcome in this study, we will have an alternative for this test in places where there is not enough room, benefiting the assessment of COPD patients' functional capacity. In the literature, there are still some controversies about performing the test on a treadmill or in a corridor and whether there is interference with the distance walked. Our hypothesis is that there is no interference with the distance walked, and thus we have one more option to perform the test in case there is no 10-meter corridor available.

Spirometry tests will be performed using ULTIMA CPX equipment. Volunteers will perform the tests twice, on different days (see protocol description), in a corridor and on a treadmill, until reaching their limit of tolerance. In the test performed on the treadmill and in the one performed in the corridor, subjects will simultaneously use the VO 2000. And the volunteers will fill out the Saint George's Respiratory Questionnaire (SGRQ).

Inclusion Criteria:

• clinically stable
• not dependent on oxygen to exercise
• diagnosis of COPD according to the GOLD

Exclusion Criteria:

• cognitive deficit or musculoskeletal
• in process of exacerbation
• have performed pulmonary rehabilitation