The introductory presentation of the symposium "Mental Fatigue, Boredom, and Performance" will be structured in two parts. In the first part, the general theme of the symposium will be addressed by defining acute mental fatigue, such as a reduction in the capacity to exert mental effort during or immediately following physical exercise or cognitively demanding tasks. We will also introduce potential relationships between fatigue, boredom, and performance, particularly within the symposium's core contexts of sports performance and health. In the second part, a brief presentation of the symposium's speakers will be made, with the following order of presentation: Jelle Habay, Alison Lorcery, Alain Bouche, Thomas Mangin, and Michel Audiffren.