Many athletes have heard about gluconeogenesis, but not everyone knows what it is. Find out how this process affects the muscle growth and strength of the athlete. Gluconeogenesis is the reaction of glucose synthesis from substances of a non-carbohydrate nature. Through this process, the body can maintain the required concentration of glucose in the blood during prolonged fasting or during vigorous physical exertion. Gluconeogenesis mainly takes place in liver cells and partly in the kidneys. The most intense gluconeogenesis in bodybuilding occurs when using nutrition programs containing a small amount of carbohydrates.
You are probably wondering why the body synthesizes glucose, when, thanks to fat reserves, it can provide itself with energy for an average of two months. But in practice, everything is quite complicated and this is what will be discussed now.
The value of glucose for the body
Our muscles can use fats only to provide energy for oxidative fibers, and during aerobic exercise they are also partially intermediate. In muscles, fatty acids can only be oxidized in mitochondria. Fibers of the glycolytic type are not used by mitochondria, and for this reason, fats, but can be a source of energy for them.
In addition, the nervous system and the brain can also use only glucose as an energy source. An interesting fact is that almost half of the mass of the nervous system is made up of lipids; glucose is needed for its work. This is because brain and nerve tissue is low in fat. Moreover, they are mainly phospholipids and contain carbon atoms in their molecule, as well as cholesterol. It should be noted that cholesterol should only be in a free state.
All these substances, if necessary, can be synthesized by the brain from the same glucose or other low molecular weight substances. Mitochondria located in the tissues of the brain and nervous system are quite inert to fat oxidation. During the day, the brain and central nervous system consume about 120 grams of glucose.
Also, this substance is vital for the work of red blood cells. During the hydrolysis process, erythrocytes actively use glucose. Moreover, their share in the blood is about 45 percent. During their maturation in the inert brain, these cells lose their nuclei, which is characteristic of all subcellular organelles. This leads to the fact that red blood cells are not able to produce nucleic acids and, accordingly, oxidize fats.
Thus, red bodies only need glucose, which predetermined their metabolism, which can only be anaerobic. Some of the glucose in red blood cells is broken down to lactic acid, which then ends up in the blood. Erythrocytes in the body have the highest rate of glucose utilization and during the day they consume more than 60 grams of this substance. Note that glucose is needed, and some other internal organs and the body are forced to synthesize glucose. However, gluconeogenesis in bodybuilding can involve not only fats, but also protein compounds.
Gluconeogenesis and protein compounds
You probably already understood that proteins themselves, and the amino acid compounds that make up their composition, take part in this process. During catabolic reactions, protein compounds are broken down into amino acid structures, which are then converted to pyruvate and other metabolites. All of these substances are called glycogenic and, in fact, are glucose precursors.
There are fourteen such substances in total.Two more amino acid compounds - lysine and leucine - are involved in the synthesis of ketone bodies. For this reason, they are called ketones and do not participate in the gluconeogenesis reaction. Tryptophan, phenylalanine, isoleucine, and tyrosine can participate in the synthesis of glucose and ketone bodies, and they are called glycoketogenic.
Thus, 18 out of 20 amino acid compounds can take an active part in gluconeogenesis. It must also be said that about a third of all amino acid compounds that enter the liver are alanine. This is due to the fact that most amino acids are broken down to pyruvate, which in turn is converted to alanine.
You must understand that catabolic reactions in the body are ongoing. During normal functioning of the body, about one hundred grams of amino acid compounds are split on average daily. If you use a low-carb nutrition program, the breakdown of amino acid compounds is much faster. The rate of this chemical reaction is regulated by hormones.
Gluconeogenesis and fats
Triglyceride (fat molecule) is an ester of glycerol, the molecules of which are linked by three fatty acid molecules. When triglyceride leaves the fat cell, it cannot enter the bloodstream. However, this becomes possible after lipolysis (the so-called fat burning), during which the triglyceride molecule is broken down into fatty acids and glycerol.
The lipolysis process takes place in the mitochondria of fat cells, where triglycerides are delivered by carnitine. When the molecules that previously made up triglyceride are in the blood, they can be used for energy if needed. Otherwise, these molecules are returned to other fat cells.
In the process of gluconeogenesis, only glycerol can take part, but not fatty acids. Until that moment. As this substance is converted to glucose, another transformation takes place with it. In turn, fatty acids can be used as an energy source for the heart and muscles.
Converting fats into glucose is a very laborious process, and besides, only one molecule out of four can participate in it. If fatty acids are unclaimed, they will return to the fat cells. It is easier for the body to obtain energy from protein compounds, and for this reason muscles are very vulnerable when using low-carb nutrition programs. This process can be slowed down by the use of AAS or by consuming a small portion of carbohydrates before training. If you take carbohydrates about half an hour or a little less before the start of the session, then insulin will not have time to be synthesized. For this reason, all glucose will be used up by the nervous system, red blood cells and the brain, thereby slowing down muscle breakdown.
Of course, low-carb nutrition programs are very effective in reducing fat. But you must remember that during the period of their use, the risk of losing muscle mass increases dramatically. To avoid this, you must make adjustments to your training process.
More information on gluconeogenesis in this video: