Research suggests that two, consecutive acts of self-control lead to impaired performance. This phenomenon is termed "ego depletion." It is assumed that an act of self-control consumes energy from some limited resource leaving less energy available for a subsequent act of self-control. Study 1 tested the alternative hypothesis that people's naive theory or expectancy of the consequences of self-control influences their performance on control-demanding tasks. Participants watched an upsetting video fragment and subsequently performed a physical exercise test demanding self-control. Participants who suppressed their emotional reactions to the video showed ego-depletion: Their performance at the physical test decreased. However, if their (implicit) expectation that self-control negatively influences subsequent performance was challenged, their performance increased. Study 2 showed the existence of a dominant expectation that self-control consumes energy. These results indicate that the occurrence of the ego depletion phenomenon is strongly influenced by expectancies or schemata about self-control.