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, 1982) 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).
Method:
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. 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. 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.
Analysis/Results:
Chi-square analysis revealed a significant difference between boys and girls in PA stages (Chi-square = 12.9, p < .01). Boys were more likely to be in the 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 and the highest for maintenance. However, no significant main effect for sex and interaction effect between sex and stage were detected.
Conclusions:
The findings suggest that most adolescents were in the higher stages (action and maintenance) of PA behavior. Compared to girls, more boys have participated PA for 60 minutes or more 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).