LAUSR

BACKGROUND The aim of this study was to examine the intrapersonal, social, and physical environmental factors associated with physical activity (PA) practice in Thai adolescents. METHODS A total of 5536 adolescents aged 14-17 years participated in the survey. Confirmatory factor analyses and structural equation modeling were conducted to determine associations between intrapersonal, social, and physical environmental factors with PA. RESULTS The mean age of participants was 15.50 (1.12) years. Community environment had an overall effect on PA (β = 0.08). Perceived family support had direct (β = -0.14) and indirect (β = 0.17) effects on PA through perceived barriers (β = 0.14). Perceived barriers were directly related to PA (β = -0.23) and indirectly (β = -0.16) related to PA through self-efficacy (β = -0.14) and through perceived benefits and self-efficacy (β = -0.02). Perceived usefulness was indirectly related to PA through self-efficacy (β = 0.07). Self-efficacy was directly related to PA (β = 0.43). Girls were more likely to report more perceived barriers (βtotal = 0.13). The model explained 45% of the variance in PA. CONCLUSION Self-efficacy and perceived barriers are important intrapersonal factors, whereas perceived family support is an important interpersonal factor for PA among Thai adolescents.