Relations of age with changes in self-efficacy and physical self-concept in preadolescents participating in a physical activity intervention during afterschool care.

An inference from Piaget's theory of cognitive development suggests that preadolescents of different ages who participate in a physical activity intervention may respond differently on measures of their physical self and self-efficacy, so a field investigation was conducted to assess effects. In a sample of 105 children ages 8 to 12 yr. (42% boys, overall M(age) = 10.1 yr., SD = 0.9), participation in a physical activity intervention during afterschool care, based on social cognitive theory and incorporating instruction in self-management and self-regulatory skills, was associated with significant improvements in measures of exercise-related self-efficacy, perceived physical appearance, and physical self-concept over 12 wk. Analyses suggested, however, no difference in changes on these factors was associated with participants' age or children being in either the concrete operations or formal operations stage of cognitive development. After replication, implications for design of physical activity interventions for preadolescents were suggested.