Jo (not her real name) hobbled into my consulting room, walking stiffly and in obvious discomfort. My initial thought was that she had injured one of her knees or hips, after commencing exercising to assist with her osteoarthritis. She was nearly in tears as she told me that it burned like fire to walk, climb stairs; and to sit on the toilet was agony. She had even stopped drinking as much water to reduce her need to pee! Even lying in bed was extraordinarily painful if she had to roll over. It turns out that Jo had decided to increase the level of exercise that she had been doing, increasing the weight she was moving at the gym, on the leg press and leg extension machines from light to very heavy, very quickly.
Delayed onset muscle pain is usually a result of increased activity, with many research papers citing the eccentric phase (lengthening) of the muscle cycle being the responsible component. During the eccentric phase under load, there is microtrauma to the muscle resulting in a variety of outcomes. There are six hypothesised theories for the mechanism of DOMS, namely: lactic acid, muscle spasm, connective tissue damage, muscle damage, inflammation and the enzyme efflux. Most likely it is a combination of these factors that cause the pain.
There are not may methods that relieve the pain associated with DOMP. Returning to exercise, that is lighter will provide some temporary relief, as will NSAIDs (ibuprofen) and massage. There is little evidence at the moment that cryotherapy, stretching, homeopathy, ultrasound and electrical current modalities (TENS) assist in the reduction of pain or time to resolution. DOMPS is self-limiting to usually a couple of days.
To avoid DOMP, a gradual build in the frequency and intensity of the exercise is required. It is not unusual for even people who train frequently to develop DOMP. Indeed, there are some sports where it is felt that DOMP may result in hypertrophy of muscles (bodybuilding and powerlifting).
Jo was advised to recommence her exercise program at much lighter weight, encouraged to engage an exercise physiologist to assist with the development of a training program to reduce the likelihood of this reoccurring.