Physical activity in adolescents: analysis of the social influence of parents and friends.

OBJECTIVE To analyze the association between physical activity and social support from parents and friends on the physical activity level among adolescents. METHODS Data from 2,361 adolescents (56.6% females; mean age 16.4; SD = 1.2), from public and private high schools were analyzed. The physical activity level of the adolescents, parents, and friends were measured through a questionnaire. Parents' and friends' support and self-efficacy were measured using two previously tested scales. Data analysis was performed using the structural equation modeling in IBM® SPSS® Amos™ 20.0. RESULTS Physical activity of friends was directly associated with physical activity level of adolescents. Physical activity of the father was associated with that of their sons, and the physical activity of mother was associated with that of their daughters. An indirect association was identified between the physical activity of parents and friends with physical activity level of the adolescents, mediated by social support. Social support was directly associated with physical activity in adolescents of both genders and indirectly mediated by self-efficacy. CONCLUSIONS Parents and friends have a social influence on adolescents' level of physical activity through the mechanism of behavior modeling or through social support, mediated by self-efficacy.