Six-minute-walk test and maximum exercise test in cycloergometer in chronic obstructive pulmonary disease. Are the physiological demands equivalent?
The SMWT is a constant load exercise in COPD patients, regardless of disease severity. It imposes high metabolic, ventilatory and cardiovascular requirements, which were closer to those of CPET in severe COPD. These findings may explain the close correlation between distance walked and peak CPET VO(2).
While comparative studies should be performed with one-leg treated animals due to interaction effects, for proof-of-principle studies, operating two legs per animal may be justified as the welfare of the animals is warranted. This is a great benefit in the sense of the 3Rs because up to 50% of animals can be spared.