What defines fatigue in the context of exercise?

In the context of exercise, fatigue is predominantly characterized by the inability to maintain power output during repeated muscle contractions. This definition takes into account the physiological and psychological aspects of exercising, where sustained performance declines due to various factors such as depletion of energy stores, accumulation of metabolic byproducts, or neuromuscular fatigue. As individuals engage in a repetitive exercise regimen, their muscles may become less efficient at generating force, leading to a significant drop in their ability to perform at the same intensity level over time.

While factors like hydration and energy intake can influence overall performance and may lead to fatigue, they are not the core definition of fatigue itself. The focus on power output during contractions emphasizes the functional aspect of fatigue as it relates specifically to muscular performance, making it a more precise and relevant measure in an exercise context.