Six-minute walking test
The 6MW test was performed twice with more than 30 min
between tests to allow heart rate and dyspnea to return to
their initial resting values. Subjects were asked to walk,
during 6 min, at their own maximal pace along a perimeter of
30 m. No encouragement was given, and subjects were
informed each minute of the time remaining. A dyspnea
score was measured on a visual analog scale (VAS, 0e10 cm)
before and at the end of the test. The minimum, clinically
important difference (MCID) was set at 35 m for the 6MWD.