Why does lactic acid build up in muscles? And why does it cause soreness?

Published / by Daniel Jacks

1427449604746Panting is caused by strenuous exercise and you always do so in order to pay back the oxygen debt you owe to the muscles. The most preferred form of respiration is aerobic which involves using oxygen as one of the reagents by the bodyís power house. Some exceptions cannot be handled by aerobic respiration such as heavy lifting or evading a jaguar. In this case, the body may not be able to deliver the amount of oxygen the muscles need to deliver the enormous amount of energy which forces the muscles to use anaerobic respiration.

Glycolysis is the process by which glucose is broken down in a series of reaction to form pyruvate. In cases where there is plenty of oxygen in the body, pyruvate is further broken down to increase its efficiency or rather its energy output. Under low supply of oxygen, the pyruvate is broken down to lactate, a substance that breaks down glucose and in the process releasing energy. This process is sustained for periods of about 3 minutes. Lactate will keep on accumulating in the muscles and reaches a very high level.

Lactate disrupts other metabolites and scales up the level of acidity in the muscles and therefore results in a number of side effects.  This means that anaerobic respiration may slowly decay due to high levels of acidity making it virtually impossible to breakdown glucose to energy. This process is somewhat counterproductive because the muscles are the largest producers of energy yet it produces substances that block its energy production process. It doesnít matter what you think about it but the fact is, nature designed the muscles with that mechanism so that it can prevent damage of extreme exertion.

Lactic acid or simply lactate is not actually the chief perpetrator of muscle soreness as most people claim after a strenuous exercise. The burning sensation is always caused by a combination of a lactic acid with other dozens of metabolites though it is not clear which exact metabolites are responsible. The reason why you feel so much pain is because the body forces you to stop so that it can recover and also protect itself from being overworked.

The soreness of the muscles that is always felt even after some few days was found to be less affected by the lactic acid as researchers examined the pain levels in relation to lactic acid level. In some cases, severe muscle tenderness and a drastic decrease in energy and motion range is caused a condition known as delayed-onset muscle soreness (DOMS), which reaches up to a maximum of 24-72 hours after a strenuous exercise.

Muscular damage and excess release of metabolites might be attributed to the cause of DOMS, though it has not been scientifically proven. However, the soreness, inflammatory-repair response, and swelling are a result of the responses to the extreme damages done to the muscles. A key factor to the development of DOMS is the nature of muscle contraction. Muscle eccentricity occurs when the muscles stretch or lengthen, such as lifting a load. This process tries to contract the muscles but a failure could occur.

Research has shown that eccentric contractions are a major source of muscular damage compared to the concentric contractions. Concentric contraction is where the muscles shorten like in the case of releasing a load. This observable accounts for the severe DOMS experienced when you try to run downhill.

As the problem of delayed-onset muscle soreness continuous to cause havoc amongst people who perform extreme physical exercises, physiologists, on the other hand, are burning the midnight oil to come up with a solution to this menace. The researchers are now focusing on the development of anti-inflammatory drugs and even come up with some supplements to help prevent muscle soreness. A treatment to the problem could also be a breakthrough.

But for now, the muscle soreness still remains under active research with no available recommendations yet. Remember the inflammation of the muscles can be significantly reduced if you take some anti-inflammatory drugs which are available at your local chemist. The anti-inflammatory drugs may also help to reduce muscle soreness. Unfortunately, the reduced muscle soreness would spell some negative effects on the muscle cell repair and may end up taking a few weeks to normalize. You have an idea now on what happens behind the scenes.

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