What Makes Them Move? An Agent-Based Model of Childhood Physical Activity

Engaging in moderate-to-vigorous physical activity (MVPA) in early childhood can have both immediate and long-term health benefits. Strategies for consistently supporting this are currently unknown, largely due to the vast number of potentially interrelated and dynamic contributing factors that may also be heterogenous across children.

We developed an agent-based model (ABM) that represents children ages 3-9 who can engage in MVPA in a variety of settings in which they spend time. Our model incorporates key theoretical constructs identified in the literature and is grounded in high-quality empirical evidence, primarily participant data from a cohort-based randomized controlled trial with extensive longitudinal accelerometry measurement. We assess the ABM's ability to reproduce patterns of MVPA observed in the cohort.

We uncovered a specific model representation of key pathways and settings involved in MVPA for this age group that can closely reproduce real-world MVPA across multiple a priori assessment metrics. This specification provides new insights into modeled contributors to MVPA. Within our model, the most important within-model pathway driving MVPA for girls is the quality of the built environment, while, for boys, it is the social environment; given the relative availability of the two, this might explain observed differences in MVPA in real-world settings.

In addition to immediate insights, this article provides proof of principle for a powerful tool that can further explore the etiology of childhood MVPA and inform practices and policies to positively affect early childhood PA, setting the stage for lifelong health.