To promote pro-environmental behavior (PEB), it is necessary to motivate behavior to resolve the difficulty in carrying out such actions. Therefore, as a psychological approach for motivating behavior, this study focuses on enhancing the sense of control over behavior and proposes a method to improve this sense of control. Since PEB often causes physical effort, we propose a task that includes strength training to reduce the physical effort. The purpose of this study is to develop an experimental task aimed at improving the sense of control. We conducted an experiment using this task. The results indicated that participants experienced an increase in their sense of control and reported higher levels of active pleasure and self-efficacy. Additionally, the frequency of pro-environmental choices increased after the strength training task.