Application of the Transtheoretical Model to Physical Exercise Behavior in Adolescents

Abstract

： Adolescent physical inactivity in China remains a pressing health concern. Guided by the Transtheoretical Model (TTM), this study examined how Decisional Balance (DB), Processes of Change (POC), and Self-Efficacy (SE) are distributed across stages of exercise behaviour and discriminate stage membership. Stratified random sampling yielded 2 100 valid respondents (13–17 y) from 14 Guangxi cities who completed the culturally adapted Adolescent Physical Exercise Behaviour Change Questionnaire (α = .80–.88). Stage distribution was skewed toward Pre-contemplation/Contemplation (57.3 %), with only 12.5 % in Maintenance (χ² = 85.3, p < .001). MANOVA showed significant stage effects (Wilks λ = .73, p < .001): DB scores declined from Precontemplation to Maintenance (η² = .02), whereas POC and SE increased progressively (η² = .18–.20). Discriminant analysis indicated that SE (.95) and POC (.88) best predicted Action/Maintenance, while DB (.97) distinguished early stages; overall classification accuracy exceeded 70 %. These findings validate the TTM in a large non-Western adolescent cohort and highlight stage-specific levers: reframing perceived “cons” for inactive youth and strengthening SE plus experiential processes for those already active. Tailored, school-based programmes that operationalise these levers may help curb physical inactivity among Chinese adolescents.