Supplementary information files for "Development and psychometric assessment of the sociocultural influences on exercise behaviours in adolescents questionnaire"

Supplementary information files for article "Development and psychometric assessment of the sociocultural influences on exercise behaviours in adolescents questionnaire"<b>Objectives</b> This research aimed to construct and psychometrically test a measure of multiple sociocultural dimensions (i.e. family, peers, media) theoretically associated with exercise behaviours/attitudes in adolescents; the Sociocultural Influences on Exercise Behaviours in Adolescents Questionnaire (SIEBAQ).<b>Methods</b><b> </b><b>and</b><b> </b><b>measurement</b> Part 1 of this study focused on measure construction and psychometric testing, involving item generation and exploratory factor analysis (EFA) to refine the item pool, with 905 adolescents (<i>M</i>age 13.66 years (SD = 0.94); girls = 442). Part 2 sought to explore the convergent validity of the SIEBAQ (<i>n</i> = 846; <i>n</i> = 414 girls).<b>Results</b> EFA resulted in a 47-item measure with a nine-factor structure (including social media modelling, parent exercise expectations, peer co-participation; α = 0.72-0.92). Correlations revealed weak-moderate significant relationships between the SIEBAQ and related constructs (e.g. compulsive exercise, sociocultural attitudes towards appearance). Regression analyses with the SIEBAQ identified social media modelling of exercise as a significant predictor of compulsive exercise in boys and girls. Proving exercise ability to significant others also significantly predicted compulsive exercise outcomes.<b>Conclusion</b> This newly developed measure holds promise. Further psychometric testing and validation of the SIEBAQ is the recommended next step to confirm the measure’s nine-factor structure identified through EFA.<br><br>©The Authors, CC BY-NC-ND 4.0