Shuttle walk tests as outcome measures: Are two incremental shuttle walk tests and two endurance shuttle walk tests necessary?

This study was undertaken in people with chronic obstructive pulmonary disease to determine differences in incremental shuttle walk test distance and endurance shuttle walk test time when two of each shuttle test were performed before (n = 53 participants) and after an exercise training program (n = 31 participants) and whether the results altered program outcomes. There was a significant increase in incremental shuttle walk test distance between the two incremental shuttle walk tests before (P < 0.001) and after training (P < 0.01). There was no significant difference in the endurance shuttle walk test time between the two endurance shuttle walk tests before (P = 0.95) or after training (P = 0.07). There was a significant increase in both incremental shuttle walk test distance and endurance shuttle walk test time after training (all P < 0.01); however, the increase was greater if the better of the two tests was reported at both time points. The incremental shuttle walk test should be performed twice before and after an exercise training program. This does not seem to be necessary for the endurance shuttle walk test; however, improvement after training was greater if the better of two endurance shuttle walk tests were used to evaluate program outcomes.