DOMS (Delayed Onset Muscle Soreness)
DOMS (Delayed Onset Muscle Soreness) is muscle pain that appears not immediately, but 24-48 hours after unfamiliar or intense exertion, especially after eccentric work (for example, downhill running).
In detail
The cause of DOMS is microdamage to muscle fibers and the subsequent inflammatory response during recovery, not the accumulation of lactic acid, as was long believed (lactate is cleared from the muscles within an hour after exertion, long before the pain appears). DOMS is a normal part of adaptation, not an injury, but severe soreness requires caution.
How to use it
Light movement (a recovery run, a walk) during DOMS usually helps more than complete rest — it boosts blood flow and slightly speeds up recovery; but don't train at the same intensity level that caused the soreness.