BackgroundThis study examined associations between motor performance in early life and leisure‐time physical activity (LTPA) participation across adulthood, and whether these changed with age.MethodsData were from 2526 participants from the Medical Research Council National Survey of Health and Development. Motor indicators were mother‐reported ages at first standing and walking, teacher‐rated games ability at age 13, and finger‐ and foot‐tapping speed at age 15. LTPA was reported at ages 36, 43, 53, 60‐64, and 68 years and classed at each age as none, moderate (1‐4/mo), or regular (≥5/mo). Associations were examined using mixed‐effects Poisson regression models with robust error variance.ResultsBetter ability at games and faster tapping speed were associated with more frequent participation in LTPA across adulthood, for example, fully adjusted relative risk of regular LTPA across adulthood (vs none) for above‐average ability (vs below average or average) = 1.46 (95% CI 1.32, 1.61); and per 10‐unit higher number of finger‐taps/15 seconds = 1.04 (95% CI 1.02, 1.07). These associations did not vary by age (P ≥ .33 for interactions with age at LTPA). Ages at reaching motor milestones were not associated with LTPA (eg, fully adjusted relative risk of regular LTPA across adulthood for walking ≤10 and ≥18 months (vs 11‐17 months) were 1.01 (95% CI 0.86, 1.20) and 0.89 (95% CI 0.75, 1.06) respectively.ConclusionsBetter ability at games and faster tapping speed in adolescence were associated with greater participation in LTPA throughout adult life; from age 36 up to age 68. Childhood motor skill interventions may therefore have the potential to promote lifelong LTPA.