Delayed onset muscle soreness (
DOMS) is the
pain and stiffness felt in
muscles several hours to days after unaccustomed or strenuous
exercise.
The soreness is felt most strongly 24 to 72 hours after the exercise.
[1][2]: 63 It is thought to be caused by
eccentric (lengthening) exercise, which causes small-scale damage (
microtrauma) to the
muscle fibers. After such exercise, the muscle adapts rapidly to prevent muscle damage, and thereby soreness, if the exercise is repeated.
[1][2]: 76
Delayed onset muscle soreness is one
symptom of exercise-induced muscle damage. The other is
acute muscle soreness, which appears during and immediately after exercise.