Abstract
Many cross-sectional studies have investigated the relationship between neighborhood physical environment and physical activity. However, few studies have examined this relationship longitudinally, and no study has examined the association between change in objective measurements of physical activity resources and change in physical activity in adults. We used longitudinal data from the Multi-Ethnic Study of Atherosclerosis (2000-2007) of 6,814 adults who were aged 45-84 years at baseline. Physical activity was assessed via a semiquantitative questionnaire at baseline and at 2 follow-up visits (approximately 1.6 and 3.2 years later). We measured the density of recreational facilities within 1 mile of each participant's home address and used linear mixed-effects models to estimate the association between change in recreational facility density and change in physical activity. After adjusting for potential confounders, we found that a greater increase in recreational density was associated with a less pronounced decline in physical activity (mean difference in annual change in physical activity for each 1-unit increase in recreational density over time = 10.3 (95% confidence interval: 0.7, 19.9)). This association was stronger in older adults. Better access to recreational facilities may benefit middle-aged and older adults by enabling them to maintain activity levels as they age.