Daily step count (and mortality)

Daily step count is the total number of walking steps accumulated in a 24-hour period, measured by accelerometer-based pedometers or wearable devices detecting vertical acceleration. It serves as a device-agnostic proxy for habitual ambulatory physical activity and is distinct from structured exercise: most steps are incidental, accumulated through everyday movement. The dose-response relationship between steps per day and all-cause mortality was quantified in the Paluch 2022 meta-analysis (15 international cohorts, 47,471 adults): HR 0.47 (95% CI 0.39-0.57) in the highest quartile (~10,900 steps/day) versus the lowest (~3,550 steps/day). Restricted cubic spline modelling showed the mortality risk curve flattening at approximately 6,000-8,000 steps/day in adults aged 60 and older, and at 8,000-10,000 in younger adults — not at 10,000. The widely cited 10,000-step target has no evidence-based origin; it derives from a 1965 Japanese marketing campaign for a pedometer trademarked "Manpo-kei" (literally "10,000-step meter"). All current evidence is observational: prospective cohort studies cannot exclude residual confounding or reverse causation, and no long-term randomised trial has tested mortality endpoints.