Differences in determinants of aerobic and muscle strengthening physical activity among college students: a reasoned action approach.

While there is a concerted effort to promote physical activity (PA) across United States government and non-governmental organizations, interventions typically focus on aerobic forms of PA, leaving out muscle strengthening PA. The purpose of this study was to operationalize the Reasoned Action Approach (RAA) to explain theory-based correlates of aerobic and muscle strengthening PA, which can provide targets for future public health interventions. Theory-based correlates of both PA behaviors were evaluated using logistic regression analyses, and intentions predicted a significant amount of aerobic PA (14.9%) and muscle strengthening PA (30.7%). Theory-based correlates of intentions to both PA behaviors were evaluated using linear regression analyses, and attitudes, perceived norms, and perceived behavioral control predicted a significant amount for aerobic PA (46.2% to 55.8%) and for muscle strengthening PA (53.9% to 59.8%). Finally, theory-based correlates of attitudes, injunctive norms, descriptive norms and perceived behavioral control were evaluated using salient beliefs, derived from an elicitation study. Results suggest that the RAA is a robust framework for predicting both types of PA behaviors. Belief-based measures also provides guidance for future public health promotion interventions and health communication strategies.