Measurement and invariance characteristics of psychosocial correlates of youth physical activity.

Objectives: Physical inactivity needs to be strategically addressed from and throughout childhood and adolescence. The youth physical activity promotion model provides a comprehensive framework for understanding and promoting physical activity in youth. This study examined psychometric characteristics of the children's attraction to physical activity scale and the perceived physical competence scale, two frequently utilized instruments to measure the underlying predisposing factors emphasized in the youth physical activity promotion model.

Design: A cross-sectional correlational research design was utilized to address the research purposes.

Methods: Participants (N=1563) were involved with a large school-based initiative involving 19 schools in two U.S. states. The children's attraction to physical activity and perceived physical competence scales were administered in the schools by the physical education teachers using a customized online platform. Confirmatory factory analysis and invariance model testing (i.e., configural, metric, and scalar invariances) were conducted with the Linear Structural Relations 8.8 software.

Results: The results supported the multidimensionality of the children's attraction to physical activity scale and demonstrated that the 6-factor measurement model was invariant by gender and mostly invariant by school level (elementary, middle, high). The scalar non-invariance across school levels was attributed to weak psychometric properties in two of the children's attraction to physical activity subscales (i.e., peer acceptance and fun of physical exertion).

Conclusions: The findings support the utility of the children's attraction to physical activity and perceived physical competence for capturing predisposing factors within the youth physical activity promotion model but document the need for refinements in several key subscales.