Final answer:
Acute exercise-induced muscle soreness is caused by microscopic damage to muscle fibers, triggering an inflammatory response and resulting in pain and discomfort. The damaged fibers undergo repair, leading to muscle strengthening and reduced soreness.
Step-by-step explanation:
When engaging in intense exercise, like resistance training, it can result in acute exercise-induced muscle soreness. This type of soreness is typically felt within 24 to 48 hours after the exercise and can last up to 72 hours. It is caused by microscopic damage to the muscle fibers, specifically to the sarcolemma and myofibrils. This damage activates an inflammatory response, leading to pain and discomfort. The damaged muscle fibers then go through a repair process, which ultimately strengthens the muscles and reduces the likelihood of future soreness.