Social Ecological Correlates of Physical Activity in Middle School Students

Background/Purpose: Despite well-documented health benefits of regular physical activity (PA), many middle school students do not participate in sufficient PA necessary to accrue the health benefits associated with PA (USDHHS, 2008). Given the fact that a physically active lifestyle during adolescence may track into adulthood, it is important to identify multilevel theory-based correlates of PA (Sallis et al., 2000). Based on the social ecological model (Sallis & Owen, 2002), multilevel correlates, such as self-efficacy, school and home physical environments, social support from parents, physical education (PE) teachers, and friends, have been consistently cited to predict individuals' PA. However, researchers have not investigated the direct and indirect relationships among these variables with middle school students. This study attempted to fill this gap by testing a hypothesized model.

Method: Participants were 539 students (189 boys, 350 girls; M_age = 12.4 years) from two southeastern public schools. They completed previously validated surveys assessing their perceptions of school and home physical environments, social support from parents, PE teachers, and friends, self-efficacy, and PA during their regular PE classes. The hypothesized model was tested using path analysis (AMOS 16.0; Arbuckle, 2007).

Analysis/Results: The path analyses indicated that the hypothesized model demonstrated a good fit to the data according to the various indices of fit: ¦Ö² (3) = 4.0, p = .257; Comparative Fit Index (CFI) = .99; Incremental Fit Index (IFI) = .99; Normed Fit Index (NFI) = .99; Root Mean Square Errors of Approximation (RMSEA) = .023 (Hu & Bentler, 1999). The model accounted for 23.6 % and 31.5 % of the variance in self-efficacy and PA, respectively. Path coefficients suggested that school physical environments, parents' support, and friends' support (b = .15, .25, .24; respectively) were directly and positively associated with self-efficacy. Additionally, home physical environments, PE teachers' support, and self-efficacy (b = .09, .13, .27; respectively) were directly and positively related to PA. The effect of the parents' support and friends' support on PA was mediated partially through self-efficacy or otherwise was a direct effect (b = .17, .17; respectively). No direct effect was found between school physical environments and students' PA.

Conclusions: The findings of this study provide empirical evidence regarding the interactions among these social ecological variables. The results highlight the importance of supportive physical and social environments on students' self-efficacy and PA. These findings have significant implications for PA interventions aimed at promoting middle school students' PA.