Abstract: The purpose of this study was to explore the relevance of integrating exercise habit strength within the framework of the theory of planned behavior. Data were obtained from 538 undergraduate students [mean age=21.19 (SD=2.57); 28.4% males] using validated questionnaires and analyzed using regression analysis and discriminant function analysis. Findings indicated that exercise has both a cognitive and an automatic component and that stronger exercise habits make exercise less intentional, with the intention-exercise relationship nearly three times stronger at lower levels of exercise habit strength than at higher levels. Further, outcome expectancies regarding health and weight management resulting from sufficient exercise did not significantly differ between most profiles that were created from exercise behavior, motivation and habit strength. The results from this study demonstrate the usefulness of incorporating measures of exercise habit strength in order to further our understanding of relevant determinants of exercise behavior. Results also indicate that health outcomes of sufficient exercise are generally well known, implying that persuasive strategies should rather shift in emphasis toward instilling a sense of exercise confidence in various situations. This potentially valuable information may allow for a more thorough understanding of exercise determinants and the development of more effective interventions that target increased exercise levels.