Life Events and Longitudinal Effects on Physical Activity: Adolescence to Adulthood

INTRODUCTION: Common life events such as getting married or gaining employment may be opportunities to intervene on health behaviors like physical activity. The purpose of this study was to determine the changes in moderate-to-vigorous physical activity (MVPA) associated with several common life events from adolescence to young adulthood. METHODS: Participants in Project EAT (ages 11 to 18 at baseline and 25 to 36 at wave 4) were surveyed at four time points from 1998 to 2016. Questions included marital status, employment status, post-secondary education completion and enrollment, and living situation between each wave. Linear regression was used to model the effect of each life event on change in self-reported MVPA. Post-hoc mediation analysis was conducted to examine whether having a child mediated the effect of getting married on the change in MVPA. RESULTS: Average MVPA declined from 6.5 hours per week at baseline to 4.3 hours per week at wave 4. Having a child was associated with a significant decrease in MVPA between waves 2 and 3 and between waves 3 and 4. Getting married and leaving parents’ home were associated with significant decreases in MVPA between waves 3 and 4. Having a child both mediated and moderated the effect of getting married on MVPA. CONCLUSION: This study provides evidence that MVPA declines both after getting married and after having a child and that these effects are not independent. Interventions to maintain or increase MVPA could profitably target couples planning to get married or have a child.