Accelerometry-Derived Physical Activity Correlations Between Parents and Their Fourth-Grade Child Are Specific to Time of Day and Activity Level

Background: The purpose of this study was to employ high-frequency accelerometry to explore parent-child physical activity (PA) relationships across a free-living sample. Methods: We recorded 7 days of wrist-mounted accelerometry data from 168 dyads of elementary-aged children and their parents. Using a custom MATLAB program (Natick, MA), we summed child and parent accelerations over 1 and 60 seconds, respectively, and applied published cut points to determine the amount of time spent in moderate-vigorous PA (MVPA). Bivariate and partial correlations examined parent-child relationships between percentage of time spent in MVPA. Results: Weak to moderate positive correlations were observed before school (r = .326, P < .001), after school (r = .176, P = .023), during the evening (r = .213, P = .006), and on weekends (r = .231, P = .003). Partial correlations controlling for parent-child MVPA revealed significant relationships during the school day (r = .185, P = .017), before school (r = .315, P < .001), and on weekends (r = .266, P = .001). In addition, parents of more active children were significantly more active than parents of less active children during the evening. Conclusions: These data suggest that there is some association between parent-child PA, especially before school and on weekends. Future interventions aiming to increase PA among adults and children must consider patterns of MVPA specific to children and parents and target them accordingly.