Goals and intentions mediate efficacy beliefs and declining physical activity in high school girls

Background: According to theory, girls who set goals about increasing their physical activity and who are dissatisfied with their current activity level are likely to form intentions to be active and to carry out those intentions, especially if they have high efficacy and control beliefs about being physically active. We tested those ideas while observing naturally occurring change during high school. Methods: A cohort of 431 black and white girls was tested at the end of their 9th- and 12th-grade academic years. Confirmatory factor analysis established the structural invariance of the measures across the 3-year study period. Structural equation modeling and panel analysis were used to determine whether changes in goal setting and satisfaction would mediate relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. Testing occurred between February and May in 1999 and 2004. Data were analyzed in 2006. Results: Goal setting and intention mediated the indirect relation between self-efficacy and change in physical activity. Perceived behavioral control and physical activity change were related directly and also indirectly by a path mediated through satisfaction and intention. Black girls had lower self-efficacy, but changes in other variables were unrelated to race. Conclusions: These observations of longitudinal relations elaborate application of self-efficacy theory and the theory of planned behavior to physical activity by showing that goal setting and satisfaction mediate the relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. The results encourage additional research to identify the sources and development of physical activity goals, and their attainment, among girls, and whether experimental manipulation of goals and intentions can mitigate the decline in girls' physical activity during high school. (Am J Prev Med 2006;31 (6):475-483) (c) 2006 American journal of Preventive Medicine