Running head: SELF-DETERMINED MOTIVATION IN EXERCISE CONTEXTS The Role of Self-Determined Motivation to the Understanding of Exercise-Related Behaviours, Cognitions and Physical Self-Evaluations

Grounded in Self-Determination Theory (Deci and Ryan, 1985), the purpose of the present study was to examine whether amotivation, self-determined, and controlling types of motivation could predict a range of exercise-related behaviours, cognitions and physical selfevaluations. Exercisers (N = 375) from ten health clubs in the North of England completed questionnaires measuring exercise motivation, exercise stages of change, number of relapses from exercise, future intention to exercise, barriers self-efficacy, physical self-worth and social physique anxiety. Controlling for age and gender, multiple and logistic regression analyses supported our hypotheses by showing self-determined motivation (i.e. intrinsic motivation and identified regulation) to predict more adaptive behavioural, cognitive and physical self-evaluation patterns compared to external regulation and amotivation. Introjected regulation was related to both adaptive and maladaptive outcomes. Furthermore, a MANOVA test revealed that exercisers in the maintenance stage of change displayed significantly more self-determined motivation to exercise compared to those in the preparation and action stages. In sum, the results illustrate the importance of promoting selfdetermined motivation in exercisers in order to improve the quality of their experiences as well as to foster their exercise behaviour. Future research should examine the mechanisms that promote self-determined motivation in exercise.