Summary/Abstract Today, most American adults and children fail to meet national physical activity guidelines. Playgrounds are located in 89% of all neighborhood parks, making them a rich resource to support physical activity in both children and adults. However, not all playgrounds are created equal, nor are they all designed to encourage physical activity for all ages. Playgrounds in lower income areas are used less and playgrounds with more features attract more users and lead to more moderate-to-vigorous physical activity. Innovative playgrounds that included facilities and amenities for adults appear to increase the number of users as well as their levels of moderate-to-vigorous physical activity (MVPA) to an even greater extent. In the past decade, playgrounds in major American cities have begun experimenting with newer, more innovative playground designs;; as yet, these spaces have not been rigorously studied to assess their impact on the physical activity of all ages. Using and adapting existing methods of systematic direct observation, we propose to study and compare innovative playgrounds to traditional post and platform playgrounds across the US to determine whether they can mitigate the multiple park use disparities seen for gender, age, and socio-economic status. In addition, we will survey 1200 adult caregivers of children in playground areas to assess how playgrounds relate to their own physical activity through active transport to the playground as well as on-site physical activity. Our specific aims are: 1) To determine whether innovative playgrounds attract more users of all ages as well as reduce gender disparities in playground use and physical activity levels;; 2) To determine whether innovative playgrounds attract a similar proportion of users relative to the local population density in low-income neighborhoods as in high-income neighborhoods;; 3) To identify the contribution of specific playground features, structures, and surfacing to playground-based MVPA and active transport to playgrounds among gender and age groups, including children 5 and under, those in middle childhood (6-12), teens (13-17), adults (18-59), and seniors (60+);; 4) To make recommendations that support more MVPA in playgrounds for all age groups. This will be the first study to examine the impact of playground design on the duration and intensity levels of physical activity among playground users of all age groups and across socio-demographic communities. Given that cities are constantly renovating and creating new playground areas, the findings from this study can inform the design of playgrounds being planned now and in the future to maximize population-level physical activity.