The fitness bug strikes.  You enrol and workout at the gym, or maybe you try going for a jog.  You finish the workout feeling invigorated.  The next morning is a very different story and your muscles ache and feel like they have no energy. This is Delayed Onset Muscle Soreness (DOMS). Despite what you may have heard or read, lactic acid is not the culprit for your aching muscles.

  The production of energy for the muscles is either aerobic or anaerobic.  During high intensity exercise the muscles need greater oxygen than can be supplied by the blood.   Anaerobic metabolism does not require any oxygen to produce energy for the muscles.   During the consumption of carbohydrates and  glucose, the cells of the body produce adenosine triphosphate (ATP).  On a basic level this reaction produces  energy for the majority of the chemical responses in the body.  Lactic acid is one of the products from anaerobic metabolism.

  Many athletes consider the generation of lactic acid negatively during exercise. They do not understand that it’s production is necessary if they are to carry on exercising in the anaerobic range}  When the body creates lactic acid, it breaks it into lactate ion (lactate) and hydrogen ion. It is believed that the hydrogen ion influences the electrical signs in the muscles and nerves, decreases energy responses and hinders the contractions of the muscles. The soreness experienced while working out is thought to be the result of hydrogen ion build-up.

  Carbohydrates are energy source for the muscles and when they are utilised for the supply of energy then they are transformed to lactate.  Lactate is a very efficient source of fuel for the muscles. Fast use of carbohydrates for energy creation while exercising speeds up the formation of lactic acid and for a short time, lactic acid can accumulate in the muscles and blood.  This results in the well-known muscle aching feelings. If the intensity of the exercise is reduced then the amount of lactate required for fuel may reaches the amount of lactate creation to reach a kind of equilibrium.

Delayed Onset Muscle Soreness (DOMS)

There is little doubt that lactic acid (H+ ions) are responsible for muscle pain during exercise.  The muscles may continue to be sore immediately after the exercise as well.  However lactic acid is not the cause of muscle soreness a day after exercise. Lactic acid is totally converted in the muscles in the hour immediately after a hard workout. There are no elevated levels of lactic acid in the muscles when Delayed Onset Muscle Soreness hits.

Studies show that Delayed Onset Muscle Soreness is most likely caused by localized damage to the the contractile fibers of the muscles and the muscle fascia – predominantly micro trauma to the muscle tissues. A day after a long workout session, the injured muscles feel painful and swollen. Chemical markers are released from the injured muscle which can stimulate the pain sensors. The morning after the workout, the muscles fibers are fatigued, have tiny tears and are normally inflammed. This is seen as being an abnormal situation by the muscle nerve cells and pain signals are sent to the brain.

Tips for minimizing the discomfort caused by DOMs typically includes exercise such as walking or swimming, gentle stretching, massage (definitely!), a warm bath, and more.  All these activities are aimed at slightly raising blood flow to the muscles and injured tissues to help fix (and not expelling non-existing lactic acid accumulation).  With regular exercise the intensity of the DOMs decreases as the muscles adjust to the new loads being placed on them.

Although any exercise can cause DOMS,the findings are overwhelming that eccentric contractions are responsible for for almost all of the DOMS discomfort   An eccentric contraction is one where the force is maintained on the muscle at the same time as the muscle is increasing in length.  The easiest example of an eccentric contraction to envisage is during the controlled lowering of the weight in a biceps curl.   The muscle fibers are still receiving the messages to contract whilst simultaneously bicep muscle fibers are lengthening.  Other examples of eccentric contractions include running downhill and the lowering phase during a squat.  Exercise physiologicists will almost always incorporate eccentric contractions during research studies into DOMS.

Research indicates that DOMS is most likely caused by localized damage to the the contractile fibers of the muscles and the muscle fascia – predominantly micro trauma to the muscle tissues. The day following a long workout session, the injured muscles feel painful and swollen. Chemical markers are released from the injured muscle which can stimulate the pain sensors. The morning after the workout, the muscles tissues are tired, have tiny tears and are swollen. This is seen as being an abnormal situation by the muscle nerve cells and pain signals are sent to the brain.

General advice for managing DOMS is a bit of stretching, light activity such as walking, massage (definitely!), a warm bath, and more.  All these activities are geared at increasing the flow of blood to the muscles to facilitate muscle repair.  With regular exercise the intensity of the DOMs decreases as the muscles adjust to the new loads being placed on them.