Cheung, Hume & Maxwell 2003, Delayed onset muscle soreness

Sports Medicine review of delayed onset muscle soreness (DOMS). DOMS follows unaccustomed, especially eccentric, exercise; soreness appears around 12 to 24 hours afterwards, peaks at 24 to 72 hours and resolves within 5 to 7 days. The review attributes it to microscopic muscle and connective-tissue damage with subsequent inflammation, and explicitly rejects the lactic-acid explanation. Soreness is a poor proxy for the size of the underlying damage. No treatment strategy reliably removes it: most modalities give inconsistent or only short-term symptomatic relief.