What physiological response characterizes DOMS?

Delayed Onset Muscle Soreness (DOMS) is primarily characterized by microtears in the muscle fibers that occur as a result of unaccustomed or intense physical activity. These microtears trigger an inflammatory response in the body, which contributes to the soreness and stiffness felt in the muscles a day or two following the exercise.

As muscles repair, the inflammation can lead to pain and discomfort, which is the hallmark of DOMS. This response is a normal part of the body's adaptation process to increase strength and improve performance over time. Recognizing this physiological phenomenon helps athletes and trainers understand that soreness is often a sign of the muscles adjusting to new levels of stress, rather than an indication of injury.

The other choices do not accurately describe DOMS. Immediate severe muscle cramping typically occurs during or right after intense physical activity, not days later. Instant recovery and soreness relief is not consistent with the delayed nature of DOMS, and complete muscle repair with no pain contradicts the very definition of DOMS, which encompasses soreness as a key feature of the recovery process.