The course of gait speed during a 400m walk test of mobility limitations in community-dwelling older adults

IntroductionLong-distance walk tests, when performed as fast as possible, are widely used to assess cardiorespiratory fitness. In contrast, the 400‑m walk test (400MWT) with the instruction to walk with usual pace is often incorporated into epidemiological studies to measure mobility limitations [1,2,3]. Compared to other functional outcome measures such as the short physical performance battery (SPPB), it is less prone to ceiling effects in high-functioning older adults [4] and mean usual gait speed can be calculated from completion time.Habitual/usual gait speed is increasingly recognized as a vital sign [5].…