Muscle soreness in a racehorse post-race is primarily due to what process?

Muscle soreness in a racehorse after a race is primarily attributed to anaerobic metabolism. During intense exercise, such as racing, horses rely on anaerobic pathways for energy production when oxygen supply to the muscles is insufficient to meet the high demand. This anaerobic process generates ATP quickly but also produces lactic acid as a byproduct.

The accumulation of lactic acid in the muscle tissue contributes to the sensation of soreness and discomfort. As lactic acid builds up, it can lead to metabolic disturbances and irritate the muscle fibers, which might manifest as soreness in the days following exertion. The recovery process involves the clearance of this lactic acid and the restoration of normal muscle function, which is often accompanied by delayed onset muscle soreness.

In contrast, aerobic respiration, while critical for energy production during lower-intensity, longer-duration activities, is not the primary contributor to muscle soreness in high-intensity efforts. Myofibrillar hypertrophy refers to the process of muscle fiber growth rather than immediate soreness from strenuous activity, and changes in resting membrane potential pertain to nerve impulses and muscle contraction but are not directly responsible for post-exercise soreness. Therefore, the emphasis on anaerobic metabolism provides the best explanation for the muscle soreness experienced by racehorses after