DOMS
(DELAYED ONSET MUSCLE SORENESS)

It has happened to everyone: the morning following a hike in the mountains, a run, a football or tennis match, a session at the gym and especially after a long period of inactivity, to feel an intense pain in the muscles used the previous day. This pain, referred to as DOMS, also presents itself as pressure and can also be accompanied by a real muscle swelling. It normally increases during the day and often becomes even stronger the next day, 48 hours after the activity and then goes down gradually, until it disappears completely in the next two to three days.

Too many times I have heard friends and colleagues talk about the pains of the day following an intense workout. It is commonplace to think that the muscle aches of the next day are caused by “lactic acid”. It is now clear that this is not the case at all. In fact, lactic acid is disposed of in a few minutes after an intense effort and the next day there is no trace of it inside the body.

The causes of DOMS are to be found in the damage of myofibrille and perimuscular connective tissues:

1. Alterations in the permeability of sarcolemma, with Na/K pump deficits and resulting electrolyte imbalances;
2. Ph is lowered creating an acidic environment that activates protein-action lysosomal enzymes;
3. Myofibrile lysis;
4. Triggering inflammation.

Not all people get it and indeed it doesn’t happen for certain types of metabolism.

When it is present, however, it is certainly proportionate to our level of sedentary lifestyle and to attribute to the fact that we have practised new exercises or performed new techniques (e.g. downhill running, technical tutorials, card changes).

Muscle stretching and shortening under tension and high speed contribute to DOMS, especially with very elongated muscle. Typical example are the jumps made in complete crouching with bounce upwards. To understand why DOMS appears only after certain types of exercises, however, it is necessary to understand the difference between the two main types of muscle contraction, “concentric” and “eccentric”.

“Eccentric” contractions

This type of contraction occurs when the muscle contracts and at the same time lengthens, against resistance. For example, when you brake the fall of an object we have an eccentric contraction. When we bend our legs to lower the femoral quadriceps muscle must contract to slow down the descent, otherwise we could not resist the force of gravity and we would fall quickly. The quadriceps exerts an eccentric force. Other typical examples of eccentric contraction are: downhill run, braking after a sprint, the corner entry of a skier, a jump down.

“Concentric” contractions

Concentric contractions occur whenever the muscle contracting shortens. Lifting a weight with one arm the biceps performs a concentric contraction, when we get up from a chair the quadriceps contracts to shorten concentrically, when we push in a leg press from 90 degrees up to 0 degrees is a concentric contraction, followed by an eccentric from 0 to 90 degrees.

During eccentric contraction the muscle that bares the weight is in fact stretched while it is contracted and if the effort is high some of its structures do not hold the tension, breaking and leaking several substances which are also traceable in the blood for a few days (such as the CK), that initiate an inflammatory process. As this process takes several hours to fully develop, the delay and duration of the onset of DOMS symptoms is explained. DOMS, however, has nothing to do with localized and acute muscle injuries, such as straining and tearing, which are macroscopic structural subsidence and localized to very limited areas of a muscle and that cause acute pain during activity. The typical Sunday hiker’s morning pain was not the tiring part of the hike, that is, the climb to the summit, but the most fun one, that is, the descent made cheerfully at a brisk pace.

DOMS only happens if a certain eccentric movement is unusual, so in subjects without training in that specific type of movement. The repetition of the same type of movement makes the muscle suitable to withstand eccentric contractions without suffering the damage and, therefore, without causing the DOMS anymore.

Until the pain in the muscle has ceased, you shouldn’t train the same muscle at the same intensity. DOMS can also be due to poor muscle adaptation to the type of training, periodicity of the sessions, and too intense pain could be synonymous with cellular imbalance. In a properly exercised muscle apparatus, the amount of pain will be directly proportional to the amount of stress applied; in detail, both load, number of repetitions, work range (greater or less muscle lengthening to precede the same contraction), recovery time, technique used, will prove to be the direct modulators of the amount of stress. In the meantime you will have the process of cellular regeneration, that is, the muscle adjustment that will determine the subsequent growth (in a directly proportional or almost proportional form). It is easy to guess that, as long as it “passes” the “renewal” process, it will not be appropriate to insist on further stressful actions.

Be careful then, if the discomfort does not disappear within the first 5-10 days it could be symptom of:

• Training is too intense or wrong;
• Inadequate warm up;
• Inadequate cool down;
• Eating problems:
• Other causes (stretching, tearing, bruises)

1. DOMS, therefore, is not “mandatory”.
2. Very strong DOMS rarely indicates better or more effective training.
3. DOMS is a purely muscular symptoms, although in special circumstances (the first uphill session, for example) may also affect tendons.
4. Contrary to popular belief, if you get moving the next day and in the following days, albeit mildly, the pains that follow the first workouts disappear much more quickly than if you stay in absolute rest.
5. If you train regularly you will no longer have pains, unless you have particularly demanding workouts or intense muscle stimuli.

In conclusion, we can say that the presence of delayed onset muscle aches is a symptom of intense and effective training, but this is not to be searched for continuously.

The annoying presence of DOMS can be avoided with the right training schedule, which must be gradual and personalized, even depending on whether or not these pains are present.

Fonte: American College of Sports Medicine