Delayed onset muscle soreness

Starting or continuing an exercise programme may be easier if you understand what muscle soreness is and what to do about it.

Even though the benefits of regular exercise are well known, many of us don't do it. One reason may be that pain or discomfort sometimes goes along with fitness activities. But starting or continuing an exercise programme may be easier if you understand what muscle soreness is and what to do about it.

All of us have felt the sore after a workout. If you are like most individuals, you probably blew it off, took a few days off from your training and chalked it up to an overly aggressive workout, or the buildup of lactic acid in the muscles.

The feeling of pain, stiffness or discomfort in muscles that occurs a day or so after a work out is known in the scientific community as Delayed Onset Muscle Soreness. Because nobody wants to go around saying that mouthful, most usually just call it "DOMS" for short. Even though DOMS has been under scientific scrutiny since the turn of the century, at the present time, the actual biological process behind it remains a mystery. What is known is that DOMS is a complex process, and every piece of the puzzle uncovered, makes it all the more mysterious.

Sorting Out Soreness

Aside from the pain of muscle injuries such as strains, there are two common kinds of exercise-related muscle soreness. One is acute soreness, which occurs during or immediately after exercise; the other kind is delayed-onset muscle soreness (DOMS), which develops 12 hours or longer after exercise.

Acute soreness. Muscle soreness during and immediately after exercise usually reflects simple fatigue, caused by a buildup of chemical waste products of exercise. If so, the discomfort will often subside after a minute or two of rest.

Once the soreness goes away, you can usually continue exercising without any residual effects. If discomfort persists despite a rest period, you should stop your activity and rest the part of the body that is involved. You should not proceed with your workout until you're able to exercise that area without pain.

DOMS - Delayed onset muscle soreness.

If you have just begun exercising, or perhaps started an activity after a long break, you might become very sore after exercising. This is probably delayed onset muscle soreness, which should not put you off from your new activity. Such symptoms are a normal response to unusual exertion and are part of an adaptation process that leads to greater strength once the muscles recover.

What is DOMS?

DOMS is perception of pain and discomfort following exercise that involves increased intensity, longer duration, unfamiliar movements, or eccentric muscular work such as downhill running or plyometric. This discomfort is a normal response and most people experience it to some extent.

What are the causes and symptoms of DOMS?

Symptoms of DOMS can include pain, muscle soreness, stiffness, swelling and loss of strength. Pain and tenderness usually hit the high point 1 to 3 days after exercise and subside within 7 days. Stiffness and swelling can peak 3 to 4 days after exercise and generally resolve within 10 days. Strength loss typically peaks within 48 hours after exercise. Full recovery can take as long as 5 days. These symptoms are not dependent on each other and do not always occur together.

Delayed onset muscle soreness (DOMS) is not a new phenomenon; research investigating the cause of delayed onset muscle soreness (DOMS) dates back to the early 1900s and several theories have been put forward to explain the underlying cause. Probably one of the most popular explanations is the accumulation of lactic acid in the muscles. Popular yes, correct, no. Blood and muscle lactate levels typically return to normal values after 30-60 minutes of recovery.

Eccentric exercise produces the most severe muscle soreness but requires relatively low energy expenditure (even less than needed for concentric exercise). Therefore if lactic acid were to cause delayed onset muscle soreness (DOMS), then muscle soreness would be expected to be greater after exercise with a higher metabolic cost (concentric activity).

In addition, we know from bitter experience that the pain associated with delayed onset muscle soreness (DOMS) peaks after 24-72 hours. When we consider that lactate concentrations return to pre-exercise levels within 60 minutes it seem ludicrous to suggest that the two are somehow related. Subsequent research has suggested that damage to the muscle ultra structure and connective tissue may be responsible for delayed onset muscle soreness (DOMS).

It is suggested that a sequence of events starting with exercise causes muscle damage and then muscle protein breakdown, resulting in cell inflammation and increased local muscle temperature. As a result pain receptors are activated, causing the sensation of delayed onset muscle soreness (DOMS). Further research suggests that muscle damage alone may not be the best explanation for the cause of delayed onset muscle soreness (DOMS). Inflammation and swelling should also be considered as they also activate and sensitise pain sensors around the muscle fibres.