An Incremental Shuttle Walk Test to Estimate Maximal Aerobic Functional Capacity

Background: The goal of the present study was to compare the maximum walking speed and peak oxygen consumption (VO2 peak) obtained during the 6-min walk test (6 MWT) and an incremental shuttle walking test (ISWT) in a trained older population. Methods: A total of 22 older adults (16 female and 6 male) with a group mean age of 70±5.8 yr (range 58 to 79) completed the 6 MWT and ISWT within a 2 wk period. Heart rate (HR) and VO2 peak were measured during each test with a portable metabolic cart (Cosmed, K4B2). The VO2 peak, the maximum walking speed and the total distance walked measured during both tests (6 MWT and ISWT) were compared. Results: A total of 110 recordings for the VO2 peak were obtained and analyzed. Strong correlations were found for the VO2 peak and the walking speed (r=0.91 and r=0.89, respectively, for 6 MWT and ISWT). VO2 peak values obtained with the ISWT were significantly greater (P < 0.05) than with the 6 MWT (21.6 ± 5.3 vs 18.9 ml/kgmin ± 4.5, respectively). There was no difference between sexes. In addition, the maximum heart rate as predicted from age during the ISWT was reached by all participants while it was not during the 6 MWT. Conclusion: Thus, the ISWT appears to a better tool to assess the maximal aerobic functional capacity in older healthy adults based on the higher VO2 peak values obtained in comparison to the 6 MWT.