Performance on fast- and usual-paced 400-m walk tests in older adults: are they comparable?

BACKGROUND AND AIMS: Fast- and usual-paced 400-m walking tests are often used to assess physical fitness or function, respectively, though it is not known how performance converges on these tests. This study aims to determine whether performance on the fast- and usual-paced 400-m walks varies based upon age and physical function. METHODS: Participants (26 men, 38 women aged 70-92) completed a fast- and usual-paced 400-m walk. The Short Physical Performance Battery was used to assess function (score range 0-12). Body mass index and health history were also assessed. RESULTS: Finish times for the fast- and usual-paced 400-m walks were 333.3 and 380.3 s, respectively (P < 0.0001), and highly correlated (r = 0.88, P < 0.001). Higher functioning participants (SPPB > 10) had greater differences between tests compared to lower functioning participants (SPPB ≤ 10) (52.9 vs. 26.2 s, P = 0.005), as did younger participants (age < 80) compared to those age 80 and older (56.8 vs. 32.8 s, P = 0.003). DISCUSSION: Older and lower functioning participants had greater convergence on the fast- and usual-paced 400-m walks. Potentially some of these lower functioning and older adults may have already performed at their maximal capacity during the usual-paced walk, while the younger and higher functioning participants were able to walk substantially faster when asked. CONCLUSIONS: Choice of walking test should consider the age and functional capacity of the population as well as whether function or fitness is of interest.