Muscle soreness

Muscle soreness is aching, tenderness and stiffness in muscles that follows unaccustomed or intense physical effort.

The delayed form, often called DOMS, typically appears a day after exercise, peaks around two days and fades within a week. It is thought to involve microscopic damage to muscle fibers and the inflammation that accompanies repair, especially after eccentric movements such as downhill running or lowering weights. Soreness is a normal response to new training loads and differs from the sharp pain of a strain or tear, which occurs during activity.

Assessment is usually straightforward from the history of recent exertion and the diffuse, symmetrical distribution of tenderness. Persistent soreness with dark urine, marked swelling or weakness warrants medical evaluation. Cannabinoids have been studied in exercise recovery in small trials, and the evidence is early and does not support any established use.