What is muscle fatigue?

Muscle fatigue refers to a temporary decrease in the muscle's ability to generate force, which often occurs after prolonged or intense activity. When we look at the correct choice, it emphasizes that difficulty in sustaining contraction is the hallmark of muscle fatigue. During physical exertion, muscles experience a depletion of energy stores and an accumulation of metabolic byproducts, which together impair their capacity to maintain effective and sustained contractions. This leads to a situation where muscles may tire and struggle to perform at their normal capacity.

In contrast, the other options relate to muscle function but do not accurately capture the phenomenon of muscle fatigue as experienced during exertion. Muscle fatigue does not involve the inability to relax or a state of inactivity, but rather a primary challenge in maintaining the required level of contraction over time. Understanding this concept is crucial for sports massage practitioners, as they need to evaluate and address muscle fatigue in clients effectively.