Abstract
Exercising regularly represents a challenging public health issue. The purpose of this study was to extend prior research based on self-determination theory by considering perceptions of conflict/instrumentality with regard to physical activity. A 6-month prospective study was conducted among 62 adults. In January, their self-determined motivation toward exercise and work was assessed by questionnaire, as well as their perceptions associated to the role of exerciser. Their presence was then controlled until the end of the season. The analyses revealed a negative relationship between self-determined motivation and role conflicts, and between this variable and observed assiduity. Those results are discussed with regard to their practical implications for exercise adherence.