LAUSR

INTRODUCTION/PURPOSE To determine personal, environmental, and participation factors that predict children's physical activity (PA) trajectories from preschool through to school years. METHODS 279 children (4.5 ± 0.9 years old, 52% boys) were included in this study. PA was collected via accelerometry at 6 different timepoints over 6.3 ± 0.6 years. Time stable variables were collected at baseline and included child's sex and ethnicity. Time dependent variables were collected at 6 timepoints (age, years) and included household income (CAD), parental total PA, parental influence on PA, and parent-reported child's quality of life, child's sleep, and child's amount of weekend outdoor PA. Group-based trajectory modelling was applied to identify trajectories of moderate-to-vigorous PA (MVPA) and total PA (TPA). Multivariable regression analysis identified personal, environmental, and participation factors associated with trajectory membership. RESULTS Three trajectories were identified for each of MVPA and TPA. Group 3 in MVPA and TPA expressed the most PA over time, with increased activity from timepoints 1 to 3, and then declining from timepoints 4 to 6. For the group 3 MVPA trajectory, male sex (β estimate: 3.437, p = 0.001) and quality of life (β estimate: 0.513, p < 0.001) were the only significant correlates for group membership. For the group 3 TPA trajectory, male sex (β estimate: 1.970, p = 0.035), greater household income (β estimate: 94.615, p < 0.001), and greater parental total PA (β estimate: 0.574, p = 0.023) increased the probability of belonging to this trajectory group. CONCLUSIONS These findings suggest a need for interventions and public health campaigns to increase opportunities for PA engagement in girls starting in the early years. Policies and programs to address financial inequities, positive parental modelling, and improving quality of life are also warranted.