Which of the following best describes peripheral fatigue?

Peripheral fatigue refers to the decrease in muscle force and power output that stems from factors within the muscle itself, rather than from central nervous system (CNS) limitations. This type of fatigue occurs when there are impairments in the contractile mechanisms of the muscle or energy supply, regardless of the nervous system's ability to initiate and sustain muscle contractions.

The option indicating the loss of force and power independent of neural drive accurately reflects this understanding, as it emphasizes the role of local muscle factors, such as metabolic depletion, ionic imbalances, or structural disruptions, as contributing causes of fatigue. This distinguishes peripheral fatigue from central fatigue, which is related to a diminished ability of the nervous system to generate signals to muscles.

In contrast, the other choices refer to different aspects of fatigue or soreness. A reduction in mental focus is more about cognitive fatigue, while increased muscle soreness post-exercise is associated with delayed onset muscle soreness (DOMS) and reflects muscle damage rather than fatigue. Muscle strain during high-intensity workouts typically refers to an acute injury rather than a general concept of fatigue. Thus, the understanding of peripheral fatigue is well captured by the notion of force and power loss that is disconnected from neural drive.