Physical activity and sedentary behavior across three time-points and associations with social skills in early childhood

BackgroundThe growth and development that occurs in early childhood has long-term implications, therefore understanding the relevant determinants is needed to inform early prevention and intervention. The objectives of the study were to examine: 1) the longitudinal associations of physical activity and sedentary behavior with social skills and 2) how physical activity and sedentary behavior track over three time-points.MethodsParticipants were from the Parents' Role in Establishing healthy Physical activity and Sedentary behavior habits (PREPS) project. A total of 251 eligible toddlers and their parents participated at baseline in 2014/15 (time 1; 1.60.2years) and a sub-sample participated at 1-year (time 2; n=79; 2.70.3years) and 2-year (time 3; n=77; 3.7 +/- 0.4years) follow-ups. Sedentary time (25 counts/15s), light-intensity physical activity (LPA; 26-419 counts/15s), and moderate- to vigorous-intensity physical activity (MVPA; 420/15s) were objectively measured with wGT3X-BT ActiGraph accelerometers, and standardized for wear time. Parents reported their children's screen time (television/video, video/computer games) at all three time-points. Parents also reported on children's social skills using the Adaptive Social Behavior Inventory (ASBI) at time-points 2 and 3, and comply (e.g., cooperates; 10 items), express (e.g., joins play; 13 items), and disrupt (e.g., teases; 7 items) subscales were created by summing items. Generalized estimating equations (GEE) were conducted to address objective one. Tracking coefficients (low: 1<0.30; moderate: 1=0.30-0.59; moderate-high: 1=0.60-0.90; high: 1>0.9) were conducted using GEE to address objective two.Results Across the study, screen time was negatively associated with express (b=-0.068, 95%CI: -0.114, -0.023) and comply (b=-0.056; 95%CI: -0.094, -0.018) scores and positively associated with disrupt scores (b=0.004; 95% CI: 0.001, 0.006). Findings were similar for television/videos but less consistent for video/computer games. No associations were observed for physical activity. Screen time significantly tracked at moderate-high levels ((1)=0.63; 95% CI: 0.45, 0.81), while all other behaviors tracked at moderate levels ((1)=0.35-0.49; p<0.01) over the three time-points.Conclusions Screen time was unfavorably associated with social skills across early childhood. Furthermore, all behaviors tracked at moderate to moderate-high levels from toddler to preschool ages. Therefore, promoting healthy physical activity and sedentary behavior patterns early in life, especially for screen time, may be important.