Mental fatigue can considerably impact physical performance, as cognitive exhaustion detracts from *motivation* and energy levels. When the brain is fatigued, decision-making becomes impaired, which affects the ability to maintain *focus* during exercise. This can lead to reduced *endurance* and slower reaction times, ultimately compromising overall performance. Additionally, mental fatigue can lower the drive to engage in physical activity, leading to potential disruption of fitness routines and negating the benefits of previous training. Understanding this relationship is crucial to developing strategies for managing fatigue effectively.