Delayed onset muscle soreness (DOMS) is the pain and stiffness felt in muscles some time after unaccustomed or strenuous exercise. The soreness usually increases in intensity in the first 24 hours after exercise, and peaks from 24 to 72 hours,
It was first (medically) described in 1902, and despite intensive research, the causes are still disputed. There are several theories - the pain may be caused by multiple small muscle fibre ruptures, or by build up of excess calcium and/or lactic acid.
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