Association between objectively measured physical activity of parents and children: The 2015 Pelotas birth cohort

The present study aims to verify the association between objectively measured physical activity (PA) of parents and child in the 2015 Pelotas Birth Cohort, a population-based Brazilian birth cohort.

The main exposures were paternal moderate-to-vigorous PA (MVPA) collected when children were 1-year of age, and maternal MVPA when children were 2-years. The outcome was children's overall PA (ENMO in mg) at 4-years of age. PA was measured using wrist-worn ActiGraph accelerometers during seven complete days. Potential confounders were maternal age, maternal and paternal education, and household asset index. Crude and adjusted analyses were performed using linear regressions.

Our analytical sample comprised 1326 children with valid accelerometer data and with both parents. Mean child PA was 48.1 mg, being higher among boys compared with girls (Boys: 50 mg, 95% CI: 49.1; 50.9; Girls: 46 mg, 95% CI: 45.2; 46.8). Children's PA at 4 years was positively associated with maternal MVPA at age 2 years (p < 0.001) and paternal MVPA at age 1 year (p < 0.001). A child with both parents in the highest tertile of unbouted MVPA presented higher overall PA (p = 0.001). Similar results were found for boys; however, for girls, paternal unbouted MVPA was not associated with overall PA.

Overall, our results showed a positive impact of maternal and parental PA over 4-year-old children acceleration. These findings could be valuable when planning evidence-based interventions and policies to promote PA in young children, providing a broader perspective over the role of parents over children's behavior.