Exercise Identity and Physical Activity Behavior During Late Adolescence: A Four Wave Cross-Lagged Panel Model

Previous studies have consistently shown that physical activity engagement declines during the transition to emerging adulthood. With physical activity being tied to many health outcomes, it is important to understand predictors of physical activity behavior. Meta-analytic evidence suggests identity is one of the strongest correlates of physical activity behavior, however, existing studies have primarily used cross-sectional designs, which has limited our understanding of the temporal relationship between these constructs. Thus, the present study explored the temporal relationship between exercise identity and physical activity behavior during the transition out of high school. This study was a secondary analysis of data from all four waves of the Application of intergrateD Approaches to understanding Physical activity during the Transition to emerging adulthood (ADAPT) prospective cohort study. A total of 1,451 Canadian adolescents completed the International Physical Activity Questionnaire-Short Form and an abbreviated version of the Exercise Identity Scale yearly during Grade 11 and Grade 12 as well as the two years post-graduation. A cross-lagged panel model was computed to explore the relationships between exercise identity and physical activity behavior. Results showed strong positive auto-correlations for exercise identity and moderate-sized positive auto-correlations for physical activity at each interval. Exercise identity positively predicted future physical activity behavior; however, physical activity did not predict future exercise identity (i.e., cross-lagged correlations). These findings support existing theory that emphasizes the role identity plays in the maintenance of physical activity. Therefore, interventions should target identity as identity appears to represent a potentially promising variable underlying physical activity engagement.