Associations between parent and child sedentary behaviour and physical activity in early childhood

Background: Parents are central to healthy development in early childhood. Study objectives were to examine the associations between parent and child sedentary behaviour and physical activity in a large representative sample of Canadian 3-5-year-olds, and to determine if associations differed between sons and daughters and mothers and fathers. Data and methods: Participants were 1,116 children aged 3-5 years and one of their biological parents from cycles 2-5 (2009-2017) of the repeated cross-sectional Canadian Health Measures Survey. Sedentary time, light-intensity physical activity (LPA), and moderate- to vigorous-intensity physical activity (MVPA) were objectively-measured in both parents and children with Actical accelerometers. Average minutes/day for all valid days, valid weekdays, and valid weekend days (n=935) were calculated. Screen time of both parents and children was parent-reported, and average hours/day were calculated. Pearson correlations and linear regression models with interaction terms were conducted. Results: In the overall sample, all of the parental physical activity and sedentary behaviours were significantly correlated with children's behaviours (r=0.08-0.20). No significant parental or child sex interactions were observed in linear regression models so models were not stratified by parent or child sex. Significant associations with small effect sizes were observed between all of the parental behaviours and children's behaviours. For accelerometer data this was consistent for total days, weekdays, and weekend days. Interpretation: Parental sedentary behaviour and physical activity may be intervention targets in early childhood. This appears consistent regardless of the sex of the parent or child. Given the small effect sizes observed, additional intervention targets should also be considered.