# Impact of a multi-level, multi-component intervention to improve elementary school physical education on student cardiorespiratory fitness: an application of the parametric g-formula

## TL;DR

A school physical education program improved children's cardiorespiratory fitness over four years, with adding a PE teacher having the biggest impact.

## Contribution

This study uses the parametric g-formula to estimate the causal impact of a multilevel PE intervention on youth fitness.

## Key findings

- 49.7% of students met fitness standards after four years of PE Works implementation.
- Adding a PE teacher alone increased the percentage of students meeting standards by 6.4%.
- Full program implementation could have increased fitness standards compliance to 57.4%.

## Abstract

School physical education is an important population-level health intervention for improving youth fitness. The purpose of this study is to determine the causal impact of New York City’s PE Works program on student cardiorespiratory fitness.

This longitudinal study (2014–2019) includes 581 elementary schools (n=315,999 4th/5th-grade students; 84% non-white; 74% who qualify for free or reduced-price meals). We apply the parametric g-formula to address schools’ time-varying exposure to intervention components and time-varying confounding.

After four years of staggered PE Works implementation, 49.7% of students per school (95% CI: 42.6%, 54.2%) met age/sex-specific cardiorespiratory fitness standards. Had PE Works not been implemented, we estimate 45.7% (95% CI: 36.9%, 52.1%) would have met fitness standards. Had PE Works been fully implemented in all schools from the program’s inception, we estimate 57.4% (95% CI: 49.1%, 63.3%) would have met fitness standards. Adding a PE teacher, alone, had the largest impact (6.4% (95% CI: 1.0, 12.0) increase).

PE Works, which included providing PE teachers, training for classroom teachers, and administrative/teacher support for PE, positively impacted student cardiorespiratory health. Mandating and funding multilevel, multicomponent PE programs is an important public health intervention to increase children’s cardiorespiratory fitness.