Abstract
Introduction: Substantial declines in physical activity (PA) have been found to occur during adolescents' transition out of high school (Kwan et al., 2012). Few studies, however, have examined the psychosocial factors related to PA prior to this transition period. The purpose our study was to examine the Health Action Process Approach (HAPA) model among a sample of impending high school graduates. Methods: Participants included 154 grade 12 students (Mage = 16.91 ±.48; n=87 males) from the baseline cohort of the MovingU Study. They completed a brief questionnaire, including measures of outcome expectancies, social norms, intentions, perceived social support, and action planning, and wore a GT9X Link accelerometer for seven consecutive days. Structural equation modeling was used to test the model. Results: Analysis revealed very good fit with the data and model X2(18)=212.95 p <.001; CFI=0.98; RMSEA=0.06; and SRMR=0.04. Outcome expectancy (β 0.29) and social norms (β 0.51) were significant predictors of intentions (42% variance explained). Path coefficients for intentions to PA (β 0.36) and action planning (β 0.65) were significant, but action planning did not predict PA. The full model including family support (β -0.26) and friends' support (β 0.20) accounted for 18.5% of the variance in PA. Discussion: Overall, the HAPA model appears effective in understanding determinants of PA among the late adolescent population. Contrary to the research with university students (Kwan et al., 2009), intention appears to have a significant role in predicting PA. Future work will examine changes in these psychosocial factors as it influences PA during the transition beyond high school.Acknowledgments: MovingU Study funded by SSHRC