Inverse effects of midlife occupational and leisure time physical activity on mobility limitation in old age--a 28-year prospective follow-up study

To evaluate in a sample of initially middle-aged municipal employees whether leisure time (LPA) or occupational physical activity (OPA) was associated with mobility limitation (ML) in old age.; Prospective population-based follow-up.; Municipalities in Finland.; Public sector employees from the Finnish Longitudinal Study on Municipal Employees (FLAME) initially aged 44 to 58 (N = 5,200).; Baseline data were collected in 1981, including LPA (average exercise within previous year: inactive (no exercise), moderate (some form of exercise ≤ 1 time per week), vigorous (brisk exercise ≥ 1 time per week)) and OPA (usual activities at work within previous year: light (light work sitting, standing, or moving around), moderate (moderate work moving around), vigorous (heavy physical work)). Number of MLs was assessed using a questionnaire (8 items) in 1985, 1992, 1997, and 2009; the latest mobility score available for each subject was used for analyses. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for LPA and OPA predicting ML were estimated in a joint Poisson regression model adjusted for survival data; the other type of PA; and sociodemographic, socioeconomic, and health-related factors.; Mean age at baseline was 50.3 ± 3.6; 56.9% of participants were female. Participants with vigorous OPA in midlife had greater risk of a unit increase in ML in old age than those with light OPA (fully adjusted IRR = 1.09, 95% CI = 1.03-1.16). Participants with vigorous LPA had lower risk of ML than inactive participants (fully adjusted IRR = 0.81, 95% CI = 0.76-0.86).; Findings suggest that LPA and OPA in midlife have independent, inverse effects on mobility in old age in terms of a harmful effect of vigorous OPA and a protective effect of vigorous LPA.