To get into the finer biochemical details, lactic acid is a byproduct of the breakdown of glucose and glycogen in a process called “glycolysis.” The first two syllables – “glyco” – refer to glucose (its molecules combine to form glycogen, which accumulates in the muscles); and the ending “liz” means splitting, disintegration. Essentially, lactic acid is a glucose molecule split in half. Why is glycolysis needed? The explanation is that the breakdown of glucose produces the so-called. pyruvates are special substances that muscle cells use as energy fuel. Under the influence of impact training, glycolysis is extremely accelerated, and too much pyruvate is formed. Not all of them go into action. Excess pyruvate is converted into lactic acid.
Cause of pain?
It has been known for fifteen years: lactic acid has nothing to do with “delayed” muscle pain – the same one that you feel a day or two after a hard workout. This pain occurs due to microscopic fiber tears during the eccentric (negative) phase of the movement. It is the lowering of the weight that causes these injuries! And if during training someone lowered the weight for you, your muscles would never hurt! And this is a scientifically established fact!
Lactic acid in action.
As lactic acid accumulates, it impedes muscle contraction, nerve conduction, and energy production. This is one of the reasons why you get tired during training. And yet, lactic acid is not just a “waste from energy production.” The paradox is that she herself is a source of energy.
The carbohydrates we get from food are not immediately “sent” to the liver to be converted into glycogen there. To begin with, they enter the circulatory system, and from there into the muscles, where they are converted into lactic acid. After this, lactic acid salts “return” to the circulatory system and enter the liver for processing into glycogen. Sometimes on the way back they use other tissues as fuel – for example, tissue from the heart, liver and kidneys.
Why does this “bypass” occur during glycogen formation? The fact is that lactic acid salts are removed from the circulatory system much faster than glucose. This allows you to “distribute” the carbohydrates coming from food without sudden spikes in insulin and without fat accumulation.
In addition, lactic acid is often used by the body as an important source of energy and raw material for the synthesis of glucose and glycogen. When you train at increased intensity, lactic acid produced in the “fast” muscle fibers moves into the “slow” fibers and serves as energy fuel for them.
Approximately 75% of lactic acid produced during exercise is used as fuel. The remaining 25% is converted to glucose in the liver and kidneys. Thus, no excess lactic acid accumulates, but a sufficient level of glucose is maintained in the blood. And this is especially important for long-term training.
But that’s not all. While working out, for example, the legs, non-working muscles (say, biceps) release lactic acid from their glycogen stores. This lactic acid travels through the bloodstream to the liver and is converted into glucose. And glucose, in turn, is sent to actively working muscles and serves as raw material for the restoration of their glycogen. Thus, through lactic acid, “non-working” muscles help restore “working” ones!
Exchange regulator.
In order for glucose to pass through cell membranes, it needs insulin. The lactic acid molecule is half the size of the glucose molecule, and it does not need hormonal support – it easily passes through cell membranes on its own. In addition, muscles release large amounts of lactic acid into the circulatory system, where it also serves as a potential fuel for energy production.
So next time, when a “would-be expert” describes to you the “horrors” of lactic acid, don’t believe it, and laugh heartily to yourself. Now you know the truth: lactic acid is not the worst enemy, but the bodybuilder’s good friend!