Do school-going children with more active modes of morning commutes walk more throughout the day?

Abstract

Boosting physical activity in school-going children has multiple health and educational benefits. One strategy to boost physical activity is to have students adopt more active commutes. However, empirical health studies suggest that students respond to physical activity interventions by cutting down their activity throughout the rest of the day. If such compensatory behavior occurs in response to commuting-based physical activity initiatives, then these initiatives may not achieve their desired outcomes. Using a dataset of walking data logged by about 7,700 Singaporean students wearing portable sensors, I examine the question: Do students who walk or take public transport to school walk more throughout the day than their peers who are driven to school, or do they compensate for more active morning commutes by walking less for rest of the day? This study triangulates three statistical approaches to identify the relationship between morning commute mode choice and walking activity: a multivariate linear regression model that includes potential confounders like students' age group, household socio-economic status and built environment characteristics around home and school; a propensity score covariate adjustment model using similar baseline covariates as the first analysis; and a fixed effects model that estimates the net impact of inter-day mode changes for each individual student. Results from all three analyses suggest that students who take public transport or walk to school log a statistically significant and substantial number of steps more than their counterparts who are driven to school. However, this positive difference is whittled away by the end of the day, which supports the hypothesis that students with more active commutes compensate by walking less throughout the day. Programs to encourage active commuting may thus have limited effectiveness in boosting students' physical activity.