A Study of Community Design, Greenness, and Physical Activity in Children using Satellite, GPS and Accelerometer Data

This study examined how being around green spaces influences children’s physical activity. Researchers collected movement and GPS data from 208 children to see where they were and how active they were throughout the day. They focused on time spent outside the home and outside school hours to better understand activity during children’s free time.

Researchers found that children were more likely to be active at moments when they were in greener areas. This effect was even stronger for children living in “smart growth” communities (i.e., neighborhoods designed to encourage walking and outdoor activity). For these children, moving from a low-greenness area to a high-greenness area increased the likelihood of doing moderate to vigorous physical activity by 39%.

When researchers compared children based on their overall daily exposure to green spaces, the differences were even more striking. Children who spent more than 20 minutes a day in the greenest areas were almost five times more active than children who had almost no exposure to greenery.

Overall, the study suggests that access to green spaces can meaningfully support children’s physical activity, especially in communities designed to make outdoor environments easy to reach and enjoy.

Abstract

This study examined relationships between greenness exposure and free-living physical activity behavior of children in smart growth and conventionally designed communities. Normalized Difference Vegetation Index (NDVI) was used to quantify children’s (n=208) greenness exposure at 30-s epoch accelerometer and GPS data points. A generalized linear mixed model with a kernel density smoothing term for addressing spatial autocorrelation was fit to analyze residential neighborhood activity data. Excluding activity at home and during school-hours, an epoch-level analysis found momentary greenness exposure was positively associated with the likelihood of contemporaneous moderate-to-vigorous physical activity (MVPA). This association was stronger for smart growth residents who experienced a 39% increase in odds of MVPA for a 10th to 90th percentile increase in exposure to greenness (OR=1.39, 95% CI 1.36–1.44). An individual-level analysis found children who experienced >20 min of daily exposure to greener spaces (>90th percentile) engaged in nearly 5 times the daily rate of MVPA of children with nearly zero daily exposure to greener spaces (95% CI 3.09–7.20).