Lactic acid: friend or foe?
You’ve probably already heard that lactic acid is the cause of all sports ailments. They say that the athlete feels bad from her, her muscles ache, cramps occur, oxygen starvation develops. In a word, enemy number one of any athlete. It’s time to put everything in its place: lactic acid really isn’t such a bad thing.
If you go into subtle biochemical details, then lactic acid is a by-product of the breakdown of glucose and glycogen in a process called glycolysis. The first two syllables – “glyco” – refer to glucose (its molecules, when combined, form glycogen accumulated in the muscles): and the ending “lysis” means splitting decay. Essentially, lactic acid is a glucose molecule that has been split in half. Why is glycolysis needed? The explanation is that glucose is formed during the breakdown, i.e. Pyruvates are special substances that muscle cells use as energy fuel.
Under the action of shock training, glycolysis is extremely accelerated, and too much pyruvate is formed. Not all of them go into action. The excess pyruvate is converted into lactic acid.
The cause of the pain?
I’ve encountered this common misconception a hundred times, but I never cease to be amazed at it! Once I was sitting on a simulator bench (I’m not messing around, by the way, but resting between sets) and I heard one “bodybuilder” say to another: “Imagine, three days have passed since that workout, and everything still hurts for me! lactic acid has accumulated … “Well, here it is again, I think. Ignorance is a terrible thing!
After all, it has been known for fifteen years: lactic acid has nothing to do with “lagging” muscle pain – the same one that you feel a day or two after a hard workout. This pain occurs due to microscopic fiber breaks during the eccentric (negative) phase of movement. Yes, yes, oddly enough, it is the lowering of the weight that causes this damage! And if during training someone lowered the weight for you (and you would only have to raise it), then the muscles would never hurt! And this is a scientifically established fact!
Concentric contraction (weight lifting) does not cause micro-tears. But the paradox is that it is during the rise that more lactic acid is produced! And if the cause of pain is lactic acid, then after concentric movements the body should hurt more! And yet in reality the opposite is happening!
Do you need a massage?
All the masseurs with whom I had to communicate repeated literally word for word the same thing: “massage removes lactic acid from the body.” And after the massage they advised to take a warm bath in order to “finally free the body from this dirty trick.” What can I say here? There is no evidence that massage and warm baths remove lactic acid from the body. But even if they did, how could it help recovery? It is clear that the accumulation of lactic acid leads to weakness (in other words, muscles get tired during training). Maybe if you do a massage right after a workout, your recovery will go faster? Let’s see what scientists have to say on this score.
This is exactly the topic of an interesting study at the University of Northern Iowa. To begin with, the participants in the experiment made a “run” on the “treadmill”. All of them were experienced runners and did a good job: in 4-6 minutes they brought themselves to complete exhaustion and thereby sharply raised the level of lactic acid salts in their blood. And then the scientists had to figure out how massage, passive rest and quiet cycling act on this lactic acid.
The athletes took a blood test immediately after running, and the second time – 20 minutes after one of the three “recovery methods.” And what happened? Both passive recovery (lying on your back) and massage have no effect on the level of lactic acid salts! But 15-20 minutes of a quiet bike ride immediately reduces it.
This, of course, does not mean that massage is useless. But only he has nothing to do with lactic acid!
Lactic acid in action
When lactic acid accumulates, it makes it difficult for muscle contractions, nerve conduction, and energy production. This is one of the reasons why you get tired during your workout. And yet, lactic acid is not just a waste of 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 that, 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, tissues of the heart, liver and kidneys.
Why Lactic acid occurs?
Why does this “workaround” occur when glycogen is formed? The fact is that lactic acid salts are removed from the circulatory system much faster than glucose. This allows you to “distribute” carbohydrates from food without sudden surges 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, the lactic acid produced in the “fast” muscle fibers is transferred to the “slow” fibers and serves as energy fuel for them.
Approximately 75 percent of the lactic acid produced during exercise is used as fuel. The remaining 25 percent 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. This is especially important for long workouts.
But that’s not all. Did you know that when working out, for example, the legs, non-working muscles (say, the biceps) secrete lactic acid from their glycogen stores? This lactic acid enters the liver with the blood stream and is converted into glucose. And glucose, in turn, is directed to actively working muscles and serves as a raw material for the restoration of their glycogen. Thus, through lactic acid, the “non-working” muscles help the “workers” recover!
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 the cell membranes by itself. In addition, muscles release large amounts of lactic acid into the circulatory system, where it also serves as a potential fuel for energy production.