Muscle fatigue is a temporary condition that occurs when muscles become less capable of generating force. This can happen during intense physical activity, leading to a decrease in performance. Factors contributing to muscle fatigue include the depletion of energy sources, accumulation of metabolic byproducts, and changes in the nervous system's ability to stimulate muscles. During exercise, muscles rely on adenosine triphosphate (ATP) for energy. As ATP levels drop and waste products like lactic acid build up, muscles may feel weak or tired. Recovery from muscle fatigue typically involves rest, hydration, and proper nutrition to replenish energy stores and clear metabolic byproducts.