2014 AAHPERD NATIONAL CONVENTION, April 1-5, Louis, MO Physical Activity, Social-Cognitive Variables, and Stages of Change in Adolescents Chaoqun Huang, PhD, Wayland Baptist University, Plainview, TX; Zan Gao, PhD, The University of Minnesota, Minneapolis, MN Abstract Methods This study was designed to evaluate whether adolescents’ physical activity (PA) behaviors, PA self-efficacy, PA response efficacy, and PA intention differ as a function of sex and stages of PA behavior change (precontemplation, contemplation, preparation, action, and maintenance). A total of 316 7th to 9th grade adolescents were recruited from a junior high school. All participants completed a four-week period motivational intervention by reading a leaflet about overweight/obesity and PA. Self- reported PA behavior, PA intention, PA self-efficacy, PA response efficacy, and stages of PA behavior change were measured. Chi-square analysis revealed a significant difference between boys and girls in PA stages. Boys were more likely to be in the action and maintenance stages compared with girls. A two-way (stage× sex) MANOVA yielded a significant main effect for stage. Follow-up analysis revealed that self-efficacy, response efficacy, intention, and PA were significantly different as a function of stages of change. Values of all these variables were the lowest for precontemplation and the highest for maintenance. However, no significant main effect for sex and interaction effect between sex and stage were detected. The findings suggest that most adolescents were in the higher stages (action and maintenance) of PA behavior. Compared to girls, more boys have participated in more than 60 minutes PA in most days of a week. The self-efficacy, response efficacy, and intention based interventions might be more effective to promote adolescents’ PA behavior especially for those with lower stages of PA behavior change. Participants: A total of 316 7th to 9th grade adolescents (156 boys, 160 girls; Mage = 13.39; 76% White) were recruited from a Title I junior high school. Research Design: All participants completed a four-week period motivational intervention by reading a leaflet about overweight/obesity and the effects of PA on preventing the threat of overweight/obesity. Measures: They self-reported PA behavior, PA intention, PA self-efficacy, PA response efficacy, and stages of PA behavior change within a physical education lesson after the intervention. Data Analysis: A Chi-square analysis was used to examine the difference between boys and girls in PA stages. A two-way (stage× sex) MANOVA was employed to test the main effects for stage, sex and interaction effect between sex and stage. Fig. 2 Self Efficacy Across Stages of Change Fig. 3 Response Efficacy Across Stages of Change Results Chi-square analysis revealed a significant difference between boys and girls in PA stages (Chi-square = 12.9, p < .05). Boys were more likely to be in the higher stages, i.e., action and maintenance stages (65%) compared with girls (53%). A two-way (stage× sex) MANOVA yielded a significant main effect for stage, Wilks’ Lambda = .52, F(16, 926) = 13.6, p < .001, η2 = .15. Follow-up analysis revealed that self-efficacy, response efficacy, intention, and PA were significantly different as a function of stages of change. Values of all these variables were the lowest for precontemplation stage and the highest for maintenance stage. However, no significant main effect for sex and interaction effect between sex and stage were detected. Fig. 4 Intention Across Stages of Change Fig. 5 PA Across Stages of Change Discussions The findings suggest that most adolescents were in the higher stages (action and maintenance) of PA behavior. Compared to girls, more boys have participated more than 60 minutes PA daily in most days of a week. The increasing trend of self-efficacy, response efficacy, and intention, and PA along the stages suggests that self-efficacy, response efficacy, and intention based interventions might be more effective to promote adolescents’ PA behavior especially for those with lower stages of PA behavior change (precontemplation, contemplation, and preparation). Introduction Regular physical activity (PA) has a positive influence on individuals’ health and quality of life across the life span. Thus, assessing and understanding PA behaviors within different populations and age groups are important. Theoretical models such as the social cognitive theory (SCT) (Bandura, 1997) and the transtheoretical model of behavior change (TTM) (Prochaska & DiClemente, 1983) have been used to explain and predict PA behaviors in adolescents. However, few studies have utilized both theories to examine PA behavior changes among this population. This study was designed to evaluate whether adolescents’ PA behaviors, PA self-efficacy, PA response efficacy, and PA intention differ as a function of sex and stages of PA behavior change (precontemplation, contemplation, preparation, action, and maintenance). References Bandura, A. (1997). Self-efficacy: the exercise of control. New York: Cambridge University Press. Prochaska, J.O., & DiClemente, C.C. (1983). Stages and processes of self-change of smoking: toward an integrative model of change. Journal of Consulting and Clinical Psychology, 51(3), 390 – 395. Fig 1 Crosstab 2014 AAHPERD NATIONAL CONVENTION, April 1-5, Louis, MO