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.