Time to restore muscle glycogen after exercise. Biochemical patterns of recovery after muscular work
What kind of beast is this “glycogen”? It is usually mentioned in passing in connection with carbohydrates, but few people decide to delve into the very essence of this substance.
Broad Bone decided to tell you all the most important and necessary things about glycogen, so that you no longer believe in the myth that “fat burning begins only after 20 minutes of running.” Intrigued?
So, from this article you will learn: what glycogen is, its structure and biological role, its properties, as well as the formula and structure of the structure, where and why glycogen is contained, how the synthesis and breakdown of the substance occurs, how metabolism occurs, and also what products are a source of glycogen.
What is it in biology: biological role
Our body needs food first of all as a source of energy, and only then as a source of pleasure, an anti-stress shield or an opportunity to “pamper” itself. As you know, we get energy from macronutrients:, and.
Fats provide 9 kcal, and proteins and carbohydrates provide 4 kcal. But despite the high energy value of fats and the important role essential amino acids Among proteins, carbohydrates are the most important “suppliers” of energy to our body.
Why? The answer is simple: fats and proteins are "slow" form of energy, because their fermentation takes a certain time, and carbohydrates are relatively "fast". All carbohydrates (be it candy or bran bread) are eventually broken down into glucose, which is necessary to nourish all cells of the body.
Structure
Glycogen- this is a kind of “preservative” of carbohydrates, in other words, the body’s energy reserves - glucose stored in reserve for subsequent energy needs. It is stored in a water-bound state. Those. glycogen is a “syrup” with a calorie content of 1-1.3 kcal/g (with a calorie content of carbohydrates of 4 kcal/g).
In fact, the glycogen molecule consists of glucose residues; it is a reserve substance in case of lack of energy in the body!
The structural formula for the structure of a fragment of the glycogen macromolecule (C6H10O5) looks schematically like this:
What type of carbohydrates is it?
In general, glycogen is a polysaccharide, which means it belongs to the class of “complex” carbohydrates:
What products contain
Only carbohydrate can go into glycogen. Therefore, it is extremely important to keep the carbohydrate level in your diet at least 50% of the total calories. By consuming a normal level of carbohydrates (about 60% of the daily diet), you preserve your own glycogen to the maximum and force the body to oxidize carbohydrates very well.
It is important to have baked goods, cereals, cereals, various fruits and vegetables in your diet.
The best sources of glycogen are: sugar, honey, marmalade, jam, dates, raisins, figs, watermelon, persimmon, sweet pastries.
Persons with liver dysfunction and enzyme deficiency should be wary of such foods.
Metabolism
How does the creation and breakdown of glycogen occur?
Synthesis
How does the body store glycogen? The process of glycogen formation (glycogenesis) occurs according to 2 scenarios. The first one is glycogen storage process. After a carbohydrate-containing meal, blood glucose levels increase. In response, insulin enters the bloodstream to subsequently facilitate the delivery of glucose into cells and aid glycogen synthesis.
Thanks to the enzyme (amylase), carbohydrates (starch, fructose, maltose, sucrose) are broken down into smaller molecules.
Then, under the influence of enzymes in the small intestine, glucose is broken down into monosaccharides. A significant portion of monosaccharides (most simple form sugar) enters the liver and muscles, where glycogen is stored in “reserve”. Total synthesized 300-400 gr glycogen.
Those. The very conversion of glucose into glycogen (storage carbohydrate) occurs in the liver, because liver cell membranes, unlike the membranes of adipose tissue cells and muscle fibers, are freely permeable to glucose even in the absence of insulin.
Decay
The second mechanism called mobilization (or disintegration) is triggered during periods of famine or vigorous physical activity. As needed, glycogen is mobilized from the depot and converted into glucose, which enters the tissues and is used by them in the process of life.
When the body depletes the supply of glycogen in its cells, the brain sends signals about the need to “refuel.” Scheme of glycogen synthesis and mobilization:
By the way, when glycogen breaks down, its synthesis is inhibited, and vice versa: when glycogen is actively formed, its mobilization is inhibited. The hormones responsible for the mobilization of this substance, i.e., hormones that stimulate the breakdown of glycogen, are adrenaline and glucagon.
Where is it contained and what are the functions?
Where glycogen is stored for later use:
In the liver
Glycogen inclusions in liver cells The main stores of glycogen are in the liver and muscles. The amount of glycogen in the liver can reach in an adult 150 - 200 gr. Liver cells are leaders in the accumulation of glycogen: they can by 8% consist of this substance.
The main function of liver glycogen is Maintain blood sugar levels at a constant, healthy level.
The liver itself is one of the most important organs of the body (if it is even worth holding a “hit parade” among the organs that we all need), and the storage and use of glycogen makes its functions even more responsible: high-quality functioning of the brain is possible only thanks to normal sugar levels in the body .
If the blood sugar level decreases, then an energy deficiency occurs, due to which the body begins to malfunction. Lack of nutrition for the brain affects the central nervous system, which becomes depleted. This is where glycogen breakdown occurs. Then glucose enters the blood, thanks to which the body receives required amount energy.
Let us also remember that in the liver not only the synthesis of glycogen from glucose occurs, but also the reverse process - the hydrolysis of glycogen to glucose. This process is caused by a decrease in blood sugar concentration as a result of the absorption of glucose by various tissues and organs.
In the muscles
Glycogen is also deposited in muscles. The total amount of glycogen in the body is 300 - 400 grams. As we know, about 100-120 grams of the substance accumulates in liver cells, but the rest ( 200-280 gr) is stored in the muscles and makes up a maximum of 1 - 2% of the total mass of these tissues.
Although, to be as precise as possible, it should be noted that glycogen is not stored in muscle fibers, and in sarcoplasm- nutrient fluid surrounding the muscles.
The amount of glycogen in muscles increases in the case of abundant nutrition and decreases during fasting, and decreases only during physical activity - prolonged and/or intense.
When muscles work under the influence of a special enzyme phosphorylase, which is activated at the beginning of muscle contraction, increased breakdown of glycogen in the muscles occurs, which is used to provide glucose for the work of the muscles themselves (muscle contractions). Thus, muscles use glycogen only for their own needs.
Intense muscular activity slows down the absorption of carbohydrates, while light and short work enhances the absorption of glucose.
Liver and muscle glycogen are used for different needs, but to say that one of them is more important is absolute nonsense and only demonstrates your wild illiteracy.
Use for weight loss
It's important to know why low-carb, high-protein diets work. An adult’s body can contain about 400 grams of glycogen, and as we remember, for every gram of reserve glucose there is approximately 4 grams of water.
Those. about 2 kg of your weight is the mass of glycogen aqueous solution. By the way, this is why we actively sweat during training - the body breaks down glycogen and at the same time loses 4 times more fluid.
This property of glycogen also explains the quick results of express diets for weight loss. Low-carbohydrate diets provoke intensive consumption of glycogen, and with it fluids from the body. But as soon as a person returns to a normal diet containing carbohydrates, animal starch reserves are restored, and with them the liquid lost during the diet. This is the reason for the short-term results of express weight loss.
Impact on sports
For any active physical activity ( strength exercises V gym, boxing, running, aerobics, swimming and anything that makes you sweat and strain) the body needs 100-150 grams of glycogen per hour of activity. Having spent glycogen reserves, the body begins to destroy first muscle, then fat tissue.
Note: If we're talking about not about long-term complete fasting, glycogen stores are not completely depleted because they are vital. Without reserves in the liver, the brain may be left without a supply of glucose, and this is deadly, because the brain is the most important organ (and not the butt, as some people think).
Without muscle reserves it is difficult to perform intense physical work, which in nature is perceived as an increased chance of being eaten/without offspring/frozen, etc.
Training depletes glycogen stores, but not according to the scheme “we work on glycogen for the first 20 minutes, then we switch to fats and lose weight.”
As an example, take a study in which trained athletes performed 20 sets of leg exercises (4 exercises, 5 sets each; each set was performed to failure and ranged from 6-12 repetitions; rest was short; total training time was 30 minutes).
Anyone familiar with strength training understands that it was by no means easy. Before and after the exercise, they took a biopsy and looked at their glycogen levels. It turned out that the amount of glycogen decreased from 160 to 118 mmol/kg, i.e. less than 30% .
So, in passing, we dispelled another myth - it’s unlikely that during a workout you will have time to exhaust all your glycogen reserves, so you shouldn’t grab food right in the locker room among sweaty sneakers and foreign bodies, you obviously won’t die from “inevitable” catabolism.
By the way, you should replenish glycogen stores not within 30 minutes after training (alas), but within 24 hours.
People vastly exaggerate the rate of glycogen depletion (like many other things)! They like to immediately throw “coals” during training after the first warm-up approach with an empty bar, otherwise “depletion of muscle glycogen and CATABOLISM.” I lay down for an hour in the afternoon and the liver glycogen was gone.
We are already silent about the catastrophic energy costs of a 20-minute snail's run. And in general, muscles eat almost 40 kcal per 1 kg, protein rots, forms mucus in the gastrointestinal tract and provokes cancer, so that as many as 5 extra kilos on the scale (not fat, yeah), fats cause obesity, carbohydrates are deadly (I'm afraid -I'm afraid) and you will definitely die.
The only strange thing is that we generally managed to survive in prehistoric times and did not go extinct, although we clearly did not eat ambrosia and sports nutrition.
Please remember that nature is smarter than us and long ago regulated everything with the help of evolution. Man is one of the most adapted and adaptable organisms that is able to exist, reproduce, and survive. So no psychosis, gentlemen and ladies.
However, training on an empty stomach is more than pointless. “What to do?” you might think. You will find out the answer in the article, which will tell you about the consequences of fasted training.
How long does it take to spend?
Liver glycogen is broken down when blood glucose concentrations decrease, primarily between meals. After 48-60 hours of complete fasting, glycogen stores in the liver are completely depleted.
Muscle glycogen is consumed during physical activity. And here we return to the myth again: “To burn fat, you need to run for at least 30 minutes, since only at the 20th minute the body’s glycogen reserves are depleted and it begins to be used as fuel.” subcutaneous fat", only from a purely mathematical side. Where did this come from? And the dog knows him!
Indeed, it is easier for the body to use glycogen than to oxidize fat for energy, so it is used first. Hence the myth: you must first use up ALL glycogen, and then fat will begin to burn, and this will happen approximately 20 minutes after the start of aerobic training. Why 20? We have no idea.
BUT: no one takes into account that It's not so easy to use all the glycogen and the matter will not be limited to 20 minutes.
As we know, the total amount of glycogen in the body is 300 - 400 grams, and some sources say 500 grams, which gives us from 1200 to 2000 kcal! Do you have any idea how much you need to run to burn off such a ton of calories? A person weighing 60 kg will have to run at an average pace from 22 to 35 kilometers. Well, are you ready?
Depleted glycogen :) You will find a list of them at the bottom of the page.
Glycogen is the main fuel reserve used by our body. Glucose, produced by the body from carbohydrates consumed in food, serves as a source of energy throughout the day. Sometimes it happens that glucose reserves are used up and are not restored. In such a situation, the body begins to use up its energy reserves, that is, glycogen stored in muscle mass and liver cells, converting it into glucose. Physical activity, illness, and certain dietary habits can cause glycogen stores to deplete more quickly. Glycogen stores can be restored different ways, depending on what exactly led to their reduction.
Steps
Part 1
Glycogen restoration after physical exerciseDrink sports drinks. Consuming these drinks during sports competitions will provide your body with a constant supply of carbohydrates; In addition, the caffeine contained in some drinks also increases endurance. Sports drinks also contain sodium and potassium, which are essential for maintaining electrolyte balance.
Use insulin or other diabetic medications. In cases of pancreatic dysfunction, both oral administration and intravenous injection of appropriate drugs help.
Stick to your diet and exercise routine. Even the slightest changes can lead to undesirable results. Before changing your diet or exercise routine, consult your doctor.
Manage a hypoglycemia episode. In patients with diabetes mellitus, hypoglycemia develops quite quickly. Warning signs include dizziness, fatigue, confusion, difficulty understanding what others say, and difficulty speaking.
Prepare an emergency kit. Many people with diabetes carry a small first aid kit containing glucose gel or tablets and perhaps a syringe containing a glucagon injection and simple instructions for others on how to help if necessary.
Tell family members and friends about first aid measures. In the event of an acute attack of hypoglycemia, a patient with diabetes will not be able to administer the injection on their own.
I received an interesting question: “ What if there was strength training for the upper body (chest/back/arms...), that is, the legs were not used, so the glycogen reserve remained in them, and after strength training you went to treadmill, then the fat will not “burn”, because There is glycogen left in the legs, and that is what the body will use, right?»
What is glycogen?
Glycogen is a form of storage of carbohydrates in the body. Glycogen is mainly stored in the liver and muscles. The liver is responsible for a large number of important functions, incl. and for carbohydrate metabolism. The concentration of glycogen in the liver is higher than in the muscles (10% versus 2% of the weight of organ tissue), but still more glycogen is contained in the muscles, since their mass is greater. By the way, other tissues and organs of our body - the brain, kidneys, heart, etc., also contain glycogen reserves, but scientists have not come to a final conclusion regarding their functions. Glycogen in the liver and skeletal muscles ah perform different functions.
Glycogen from liver mainly necessary to regulate blood glucose levels during periods of fasting and calorie deficit.
Glycogen from muscles provides glucose to muscle fibers during muscle contraction.
Accordingly, the glycogen content in the liver decreases during fasting, calorie deficit, and the muscle glycogen content decreases during training in the “working” muscles. But is it only in the “working” muscles?
Glycogen and muscle function.
Several studies have been conducted ( At the end of the article I will leave a link to a full review of all sources), during which a skeletal muscle biopsy was performed after intense physical activity in a group of volunteers. It was found that in “working” muscles the level of glycogen decreases significantly during exercise, while the level of glycogen in inactive muscles remains unchanged. By the way, endurance is directly related to muscle glycogen levels; fatigue develops when glycogen stores in active muscles are depleted ( so don’t forget to eat 2 hours before training to show maximum results).
Glycogen is a “reserve” carbohydrate in human body, belonging to the class of polysaccharides.
It is sometimes mistakenly called "glucogen". It is important not to confuse both names, since the second term is a protein hormone antagonist of insulin, produced in the pancreas.
What is glycogen?
With almost every meal, the body receives glucose, which enters the blood in the form of glucose. But sometimes its quantity exceeds the body’s needs and then the excess glucose accumulates in the form of glycogen, which, if necessary, is broken down and enriches the body with additional energy.
Where are stocks stored?
Glycogen reserves in the form of tiny granules are stored in the liver and muscle tissue. This polysaccharide is also found in the cells of the nervous system, kidneys, aorta, epithelium, brain, embryonic tissues and the mucous membrane of the uterus. The body of a healthy adult usually contains about 400 g of the substance. But, by the way, during increased physical activity the body predominantly uses glycogen from muscles. Therefore, bodybuilders should additionally saturate themselves with high-carbohydrate foods approximately 2 hours before training in order to restore their reserves of the substance.
Biochemical properties
Chemists call a polysaccharide with the formula (C6H10O5)n glycogen. Another name for this substance is animal. And although glycogen is stored in animal cells, this name is not entirely correct. The substance was discovered by the French physiologist Bernard. Almost 160 years ago, a scientist first discovered “spare” carbohydrates in liver cells.
“Spare” carbohydrate is stored in the cytoplasm of cells. But if the body experiences a sudden shortage, glycogen is released and enters the blood. But, interestingly, only the polysaccharide accumulated in the liver (hepatocide) can transform into glucose, which is able to saturate the “hungry” body. Glycogen reserves in iron can reach 5 percent of its mass, and in an adult body be about 100-120 g. Hepatocides reach their maximum concentration approximately an hour and a half after a meal rich in carbohydrates (confectionery, flour, starchy foods).
In muscle composition, the polysaccharide occupies no more than 1-2 percent of the tissue mass. But, taking into account the total area of the muscles, it becomes clear that the glycogen “deposits” in the muscles exceed the reserves of the substance in the liver. There are also small reserves of carbohydrate in the kidneys, glial cells of the brain and leukocytes (white blood cells). Thus, the total glycogen reserves in an adult body can amount to almost half a kilogram.
Interestingly, the “spare” saccharide is found in the cells of some plants, fungi (yeast) and bacteria.
The role of glycogen
Glycogen is mainly concentrated in liver and muscle cells. And it should be understood that these two sources of reserve energy have different functions. Polysaccharide from the liver supplies glucose to the body as a whole. That is, it is responsible for the stability of blood sugar levels. With excessive activity or between meals, plasma glucose levels decrease. And in order to avoid hypoglycemia, glycogen contained in liver cells is broken down and enters the bloodstream, leveling the glucose level. The regulatory function of the liver in this regard cannot be underestimated, since a change in sugar levels in any direction is fraught with serious problems, including death.
Muscle reserves are necessary to maintain the functioning of the musculoskeletal system. The heart is also a muscle that stores glycogen. Knowing this, it becomes clear why most people develop heart problems after prolonged fasting or with anorexia.
But if excess glucose can be stored in the form of glycogen, then the question arises: “Why are carbohydrate foods stored on the body as fat?” There is also an explanation for this. Glycogen reserves in the body are not dimensionless. With low physical activity, animal starch reserves do not have time to be used up, so glucose accumulates in another form - in the form of lipids under the skin.
In addition, glycogen is necessary for the catabolism of complex carbohydrates and participates in metabolic processes in the body.
Synthesizing
Glycogen is a strategic reserve of energy that is synthesized in the body from carbohydrates.
The body first uses the carbohydrates it receives strategic goals, and puts the rest aside “for a rainy day.” Energy deficiency is the reason for the breakdown of glycogen into the state of glucose.
The synthesis of the substance is regulated by hormones and nervous system. This process, particularly in the muscles, is “triggered” by adrenaline. And the breakdown of animal starch in the liver activates the hormone glucagon (produced by the pancreas during fasting). The hormone insulin is responsible for the synthesis of “reserve” carbohydrates. The process consists of several stages and occurs exclusively during meals.
Glycogenosis and other disorders
But in some cases, glycogen breakdown does not occur. As a result, glycogen accumulates in the cells of all organs and tissues. Typically, such a disorder is observed in people with genetic disorders (dysfunction of the enzymes necessary to break down the substance). This condition is called glycogenosis and is included in the list of autosomal recessive pathologies. Today, 12 types of this disease are known in medicine, but so far only half of them have been sufficiently studied.
But this is not the only pathology associated with animal starch. Glycogen diseases also include aglycogenosis, a disorder accompanied by a complete absence of the enzyme responsible for glycogen synthesis. Symptoms of the disease are pronounced hypoglycemia and convulsions. The presence of aglycogenosis is determined by liver biopsy.
Glycogen, as a reserve source of energy, is important to restore regularly. So, at least, scientists say. Increased physical activity can lead to a total depletion of carbohydrate reserves in the liver and muscles, which will ultimately affect a person’s vital activity and performance. As a result of a long-term carbohydrate-free diet, glycogen reserves in the liver are reduced to almost zero. Muscle reserves are depleted during intense strength training.
The minimum daily dose of glycogen is 100 g and above. But it is important to increase this figure when:
On the contrary, people with liver dysfunction and enzyme deficiency should be careful about foods rich in glycogen. In addition, a high glucose diet involves reducing glycogen consumption.
Food for glycogen storage
According to the researchers, for adequate glycogen storage, the body must get approximately 65 percent of its calories from carbohydrate foods. In particular, to restore animal starch reserves, it is important to introduce baked goods, cereals, cereals, and various fruits and vegetables into the diet.
The best sources of glycogen: sugar, honey, chocolate, marmalade, jam, dates, raisins, figs, bananas, watermelon, persimmons, sweet pastries, fruit juices.
Effect of glycogen on body weight
Scientists have determined that about 400 grams of glycogen can accumulate in an adult body. But scientists also determined that each gram of reserve glucose binds approximately 4 grams of water. So it turns out that 400 g of polysaccharide is approximately 2 kg of glycogen aqueous solution. This explains profuse sweating during exercise: the body uses up glycogen and at the same time loses 4 times more fluid.
This property of glycogen also explains the quick results of express diets for weight loss. Low-carbohydrate diets provoke intensive consumption of glycogen, and with it fluids from the body. One liter of water, as you know, is 1 kg of weight. But as soon as a person returns to a normal diet containing carbohydrates, animal starch reserves are restored, and with them the liquid lost during the diet. This is the reason for the short-term results of express weight loss.
For real effective weight loss doctors advise not only to revise the diet (give preference to proteins), but also to strengthen physical exercise which lead to rapid consumption of glycogen. By the way, the researchers calculated that 2-8 minutes of intense cardio training is enough to use glycogen stores and loss excess weight. But this formula is suitable only for people who do not have cardiac problems.
Deficit and surplus: how to determine
The body, which contains excess portions of glycogen, will most likely report this by thickening the blood and causing liver problems. People with excessive reserves of this polysaccharide also experience intestinal dysfunction and increased body weight.
But the lack of glycogen does not go unnoticed for the body. A deficiency of animal starch can cause emotional and mental disorders. Apathy and depression occur. You can also suspect depletion of energy reserves in people with weakened immunity, poor memory, and after a sudden loss muscle mass.
Glycogen is an important reserve source of energy for the body. Its disadvantage is not only a decrease in tone and decline vitality. A deficiency of the substance will affect the quality of hair and skin. And even the loss of shine in the eyes is also the result of a lack of glycogen. If you notice symptoms of polysaccharide deficiency, it's time to think about improving your diet.
The processes of fat burning and muscle growth depend on many factors, including glycogen. How it affects the body and the result of training, what needs to be done to replenish this substance in the body - these are questions to which every athlete should know the answers.
The sources of energy to maintain the functionality of the human body are primarily proteins, fats and carbohydrates. The first two macronutrients take a certain amount of time to break down, so they are a “slow” form of energy, while carbohydrates, which are broken down almost immediately, are a “fast” form of energy.
The speed of absorption of carbohydrates is due to the fact that it is used in the form of glucose. It is stored in the tissues of the human body in bound rather than pure form. This allows you to avoid excess, which can trigger the development of diabetes. Glycogen is the main form in which glucose is stored.
Where is glycogen accumulated?
The total amount of glycogen in the body is 200-300 grams. About 100-120 grams of the substance accumulates in the liver, the rest is stored in the muscles and makes up a maximum of 1% of the total mass of these tissues.
Glycogen from the liver covers the body's total need for energy obtained from glucose. Its reserves from the muscles are used for local consumption and are spent when performing strength training.
How much glycogen is in muscles?
Glycogen accumulates in the nutrient fluid (sarcoplasm) surrounding the muscle. Muscle building is largely determined by the volume of sarcoplasm. The higher it is, the more fluid is absorbed by the muscle fibers.
An increase in sarcoplasm occurs during vigorous physical activity. With an increase in the need for glucose, which goes towards muscle growth, the volume of reserve storage for glycogen also increases. Its size remains unchanged if a person does not train.
Dependence of fat burning on glycogen
For an hour of physical aerobic and anaerobic exercise, the body requires about 100-150 grams of glycogen. When the available reserves of this substance are exhausted, a sequence enters into a reaction involving the destruction of first muscle fibers and then adipose tissue.
To get rid of excess fat, it is most effective to exercise after a long break since your last meal, when glycogen stores are depleted, for example, on an empty stomach in the morning. You need to train at an average pace to lose weight.
How does glycogen affect muscle building?
The success of strength training for muscle growth directly depends on the availability of a sufficient amount of glycogen both for training and for restoring its reserves after. If this condition is not met, during training the muscles do not grow, but are burned.
Eating too much before going to the gym is also not recommended. The intervals between meals and strength training should gradually increase. This allows the body to learn to manage available reserves more efficiently. This is what intermittent fasting is based on.
How to replenish glycogen?
Converted glucose stored by the liver and muscle tissue, is formed as a result of the breakdown of complex carbohydrates. They are first broken down into simple nutrients and then into glucose that enters the blood, which is converted into glycogen.
Carbohydrates with a low glycemic index release energy more slowly, which increases the percentage of glycogen formation instead of fat. You should not focus only on the glycemic index, forgetting about the importance of the amount of carbohydrates consumed.
Glycogen replenishment after exercise
The “carbohydrate window” that opens after training is considered best time for taking carbohydrates in order to replenish glycogen reserves and trigger the mechanism of muscle growth. In this process, carbohydrates play a more significant role than proteins. Recent studies have shown that nutrition after training is more important than before it.
Conclusion
Glycogen is the main storage form of glucose, the amount of which in the adult body varies between 200 and 300 grams. Power training Exercises performed without sufficient glycogen in the muscle fibers lead to muscle burning.
