Delayed Onset Muscle Soreness (DOMS)

It is not uncommon for exercisers to experience muscle pain and stiffness after an intense bout of weight-bearing exercise or a downhill running session, especially if after a long layoff or when just beginning a routine.

The symptoms are usually noticeable approximately 24 hours after the bout and are most obvious at about 48 hours. Years ago, it was thought that lactate formed sharp, needle-like crystals in muscle and this was the direct cause of pain. Still today, the implication of lactate as the culprit for muscle pain endures. Unfortunately, as mentioned in previous articles on this site, many unwarranted charges have been laid against this harmless yet very metabolically valuable substance including post-exercise muscle pain (see article Lactate is NOT the Culprit! ). Research has now demonstrated that lactate cannot be responsible for muscle pain, since blood lactate levels drop to normal levels within one hour of intense interval training. Recent work suggests that the reason for DOMS may be due to actual muscle damage at the fiber level. It is suspected that when one performs intense exercise, especially routines involving a large amount of eccentric contractions, there is increased potential for muscle damage. This may be due to the fact that during such a contraction; the muscle is generating tension (and attempting to shorten) but at the same time is being lengthened by the larger resistive force. These type contractions tend to cause damage and derangement of the Z disks of the fibers – the structures to which the thick (myosin) filaments are anchored.

It is suspected that the extreme forces during eccentric contractions (eccentric contractions are explained in the article Plyo…What?) cause tiny tears in the muscle membrane and in the sarcoplasmic reticulum (a net-like structure surrounding each muscle fiber storing calcium which causes muscle contraction). This damage causes increased calcium leakage into the muscles, making them less able to fully relax and may explain the stiffness associated with DOMS. The tissue damage causes an immune response in the body and the release of several chemicals in the blood, which may enhance the sensation of pain by sensitizing nerve endings in the tissue.

In summary, there is little that can be done to prevent the muscle damage associated with this condition, however it has been demonstrated that an exercise session causing DOMS provides a protective effect for future intense exercise lasting several weeks. An athlete whose event involves a large amount of eccentric contractions may specifically concentrate on the eccentric strength of the involved muscles e.g. the quadriceps for downhill runners.

References and further reading: more information on DOMS and a detailed explanation can be found in Lore of Running – a classic book in its fourth edition dedicated not only to running performance, but to cutting edge exercise physiology as well.

Find out how to purchase Lore of Running

Copyright 2005 David Petersen BS, CSCS & B.O.S.S. Fitness