Physical Activity Coparticipation and Independent Mobility as Correlates of Objectively Measured Nonschool Physical Activity in Different School Grades:The UP&DOWN Study

Background: The aim was to investigate the association of (i) parental, sibling, and friend coparticipation in physical activity (PA); and (ii) independent mobility (IM) for walking, cycling, and taking public transport with objectively measured nonschool PA on week- and weekend days in different school grades. Methods: A total of 1376 Spanish youngsters (50.8% boys; mean age 11.96 +/- 2.48 years) participated in the study. Participants reported the frequency of their parental, sibling, and best friend coparticipation in PA with them and their IM for walking, cycling, and taking public transport. PA was objectively measured by accelerometry. Results: Coparticipation in PA and IM were more frequently related to nonschool PA among adolescents than among children. Friend coparticipation in PA was positively associated with higher levels of nonschool PA in adolescents. 114 for walking and IM for cycling in adolescents were related to nonschool PA on weekdays. Conclusions: Our results highlight the need for age-focused interventions and the integration of family and friends to promote PA in youth.