This study investigated the effects of goal setting, self-efficacy, competition, and personality on the performance of a sit-up task. Prior to testing, participants were administered the Sport Orientation Questionnaire (SOQ; Gill & Deeter, 1988). Using a 2 × 2 + 1 design, 60 participants were randomly assigned to one of four conditions: (a) competition, medium goal; (b) competition, high goal; (c) no competition, medium goal; and (d) no competition, high goal. A fifth group from the same population (n = 15) was added and served as the do-best comparison group. The main effect of goal level was borderline significant (p < .059), and this effect was fully mediated by personal goal level and self-efficacy. Also, both the medium and hard goal groups significantly outperformed the do-best group. Competition did not affect performance, personal goals, commitment, or self-efficacy. The SOQ was significantly related to performance, but its effects were fully mediated by personal goals and self-efficacy.