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

<p dir="ltr">Supplementary information files for article "Development and psychometric assessment of the sociocultural influences on exercise behaviours in adolescents questionnaire"</p><p dir="ltr"><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).</p><p dir="ltr"><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).</p><p dir="ltr"><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.</p><p dir="ltr"><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</p>