Repeatability of the endurance shuttle walk test in people with chronic obstructive pulmonary disease

IntroductionWalking tests, including the endurance shuttle walk test (ESWT), have been used to assess functional capacity in people with chronic obstructive pulmonary disease (COPD). Learning effects through repeated practice have been reported for some field walking tests. However, the repeatability of ESWT at various time points, i.e. within the same day, within the week and one week apart, has not been examined. ObjectivesThis study aimed to evaluate the repeatability of ESWT overtime to determine whether or not a learning effect existed. MethodsTwenty-two participants diagnosed with COPD [age 716 years; FEV1% predicted 5424%] were recruited. Participants performed two incremental shuttle walk tests to determine the walking speed for the ESWT and a practice ESWT (E-p) to determine whether the ESWT level was appropriate. ESWT 1(E-1) and ESWT 2(E-2) were performed on the same day, 30 min apart; ESWT 3(E-3) was performed within a week from E-2; ESWT 4(E-4) was performed one week after E-3. Duration walked in each ESWT was recorded. The repeatability of the four ESWTs was analyzed using repeated measures analysis of variance. ResultsThe mean durations of E-1 to E-4 were 368 +/- 203 s, 371 +/- 182 s, 386 +/- 213 s and 367 +/- 223 s, respectively, with no time effect (F=0.18, P=0.79). ConclusionThere was no evidence of learning effect when ESWT was repeated within one day, within one week and one week apart, once the appropriate baseline level was established, showing that ESWT is repeatable in people with moderate COPD.