Psychometric validation of the belief-based physical activity questionnaire.

This study aimed to develop and validate the belief-based PA questionnaire for young Saudi females (BPAQ-YSF) in Saudi Arabia, targeting women aged 18 to 35. Six experts first participated in the conceptual validation phase, while 8 reviewed the content validity. Cross-sectional validation was carried out using a test-retest design. The study is a self-report instrument that consists of 4 parts. Each part examines various variables. The cross-sectional validation part of the study presents the results of the cross-sectional validation of the theory of planned behavior (TPB) among 820 Saudi female participants aged 18 to 35. The psychometric properties of the TPB were measured using adopted scales of direct and additional constructs, and the Cronbach alpha values indicated that the scales could deliver reliable results in a cross-cultural setting. Principal axis factoring was conducted on 24 items with oblique rotation to assess the 8 factors of the extended TPB, and the 8-factor structure explained a total variance of 76.6%. The BPAQ-YSF can help identify the psychosocial factors related to physical activity among young Saudi women. The study's findings can inform the development of interventions and culturally appropriate guidelines for PA among young Saudi women.