How Much Neighborhood Parks Contribute to Local Residents' Physical Activity in the City of Los Angeles

OBJECTIVE: To quantify the contribution of neighborhood parks to population-level, moderate-to-vigorous physical activity (MVPA). METHOD: We studied park use in 83 neighborhood parks in Los Angeles between 2003 and 2014 using systematic observation and surveys of park users and local residents. We observed park use at least 3–4 times per day over 4–7 clement days. We conducted a meta-analysis to estimate total, age group and gender-specific park use and total MVPA time in parks. RESULTS: An average park measuring 10 acres and with 40,000 local residents in a one-mile radius accrued 5301 h of use (SE = 1083) during one week, with 35% (1850 h) spent in MVPA and 12% (635 h) spent in vigorous physical activity (VPA). As much as a 10.7-fold difference in weekly MVPA hours was estimated across study parks. Parks' main contribution to population-level MVPA is for males, teenagers, and residents living within a half mile. CONCLUSION: Neighborhood parks contribute substantially to population MVPA. The contribution may depend less on size and facilities than on "demand goods" – programming and activities--that draw users to a park.