Me process model of self-control posits motivation, emotion, and attention as psychological mediators in the relationship between cognitive and physical self-control. However, this model has never been tested in a sport context. Participants (N = 69) completed 2 isometric biceps endurance trials (physical self-control task; T1 and T2), separated by a 6-min cognitive manipulation of self-control. Motivation and emotion were assessed before the respective biceps task, and attention was assessed in terms of gaze behavior on task-relevant in comparison with task-irrelevant stimuli during the biceps task (T1 and T2). To test the hypothesis that motivation, emotion. and attention mediated the relationship between cognitive and physical self-control, a parallel multiple mediator model was calculator'. The results indicate that motivation, emotion, and attention (relative change between T1 and T2) did not mediate the relationship between cognitive and physical self-control (b = -0.01, 95% bias corrected and accelerated [BCa] confidence interval [-0.06, 0.03]) and that the exertion of cognitive self-control did not necessarily lead to impaired performance. Future studies should investigate the role of task demands and older potential mediators of self-control (e.g., belief about a limited willpower).