Delayed onset muscle soreness (DOMS) is muscle pain that typically starts about one to three days after intense or unfamiliar exercise—especially work that lengthens muscles under load (eccentric movements). Cleveland Clinic explains that DOMS usually lasts only a few days and rarely more than five days as the muscle fibers repair.
The soreness should fade gradually. If pain lasts a week or more, feels sharp and constant, or comes with severe swelling or unusually dark urine, see a healthcare provider—those signs can point to injury rather than ordinary DOMS.
Source: Cleveland Clinic — Delayed Onset Muscle Soreness (DOMS)