Lactic Acid And Its Function During Training
Lactic acid, or its ionized form lactate, is a chemical compound that performs important functions in various biochemical processes such as, for example, lactic fermentation.
One of the tissues in the body that produces the most lactic acid is muscle; it does so after consuming carbon hydrates, to obtain energy. This process is known as lactic fermentation. Below we tell you everything you need to know about this molecule.
Lactic acid production
Lactic acid is mainly produced in muscle cells and red blood cells. It forms when the body breaks down carbon hydrates to form energy in the presence of low oxygen levels.
These subside during intense training or when the person has an infection or illness.
The main source of lactate is the breakdown of a carbohydrate called glycogen. This substance is a natural reserve of the body, made up of multiple sugar chains (glucose).
Its decomposition produces a lot of energy, which is why it is one of the main energy sources of the muscles.
However, the use of glucose requires oxygen and is a rather lengthy process.
For this reason, in high intensity situations, the cells shorten the path and produce energy through fermentation. It is less effective, but faster.
Although some cells are able to use pyruvate for energy, others cannot. It is for this reason that muscle is one of the tissues in which the greatest amount of lactate is produced.
Lactic acid and muscles
Lactic acid is actually a fuel, not a waste product. Muscles deliberately make it from glucose and burn it for energy.
Training leads the muscles to absorb lactic acid more effectively, and this is precisely the reason why athletes are able to exert themselves so much and for a long time.
Muscle cells are able to transform glucose into lactic acid. Later, this is absorbed and used by some cellular organelles called mitochondria, which are responsible for producing energy in the cells.
Mitochondria have a characteristic protein for carrying lactic acid within them. Intense training causes the mass of the mitochondria to double and they burn more lactic acid. As a result, the muscles work less.
Lactic acid during physical activity
With training, many cells can adapt to use more pyruvate and thus produce less lactate. As exercise intensity is increased, additional amounts of muscle fibers are recruited.
These fibers are used little when the person rests or performs light activities. Many are fast-activating and do not have a great ability to transform pyruvate into energy. Plenty of pyruvate then turns into lactate.
Lactate: a very dynamic substance
When it is produced, lactate tries to exit the muscles and enter nearby ones, such as the bloodstream or the spaces between muscle cells, where its concentration is lower.
When the lactic acid manages to enter another muscle, it is possible that it will revert to being pyruvate in order to be used for aerobic energy.
Lactate is also used by the heart as a fuel. In turn, it can travel to the liver to turn back into glucose and glycogen and start the cycle again.
Finally, it can also travel very quickly from one part of the body to another. Some amounts of lactate actually turn back into glycogen within the muscles without necessarily reaching the liver.
