Gait speed

Gait speed — typically assessed over a 4- or 6-metre walk at comfortable pace — is one of the most robust and inexpensive functional biomarkers of systemic aging, integrating muscular strength, balance, cardiorespiratory capacity, and neurological integrity into a single measurement. A large meta-analysis (Studenski et al., JAMA 2011, over 34,000 participants) showed that each 0.1 m/s increase in gait speed was associated with a 12% lower mortality hazard, and gait speed was as informative about survival as age, sex or body-mass index. Slow gait (typically <0.8 m/s) predicts incident dementia, frailty, falls, hospitalisation and mortality independently of leg strength alone, reflecting the broad integrative demands of coordinated locomotion on the central and peripheral nervous system. In clinical geroscience, gait speed is included in the Short Physical Performance Battery (SPPB) and serves as both a diagnostic marker of physical frailty and a sensitive, modifiable outcome for exercise and nutritional interventions.