Everyone who has devoted himself to sports has sometimes thought about what happens to the muscles when they receive a load. In general terms, everything seems to be clear - under the influence of nerve cells (impulses), the muscles contract and stretch, and as a result of these actions, they either acquire muscle power, or muscle endurance, or even explosive strength.

The more iron you lift, the more muscle power, the more you run (aerobics), at a slow pace, the more muscle endurance, the more you run or lift weights in an explosive style, the more explosive strength and so on ...

But after all, I want to dig a little deeper and understand what actually happens to human muscles during intense and non-intense loads. Therefore, in order to understand all this, we need to analyze what types and types of muscle fibers are and what each of them is responsible for.

Everyone who is familiar with cutting meat has seen that in different parts of the carcass, meat or muscles are quite different from each other (color, size). And this applies to any vertebrate animal, but also to humans, since in the structure of muscles we are not much different from animals. Especially clearly visible is the difference in the muscles of the chicken. Remember how the meat looks on the breast (fillet) and on the legs of this bird.

On the back it is white, and on the legs it has a reddish tint. This means that there are at least two types of muscle tissue. They decided to call them that: white muscle fibers and red muscle fibers. Thus, we came to the conclusion that in our body there are muscles consisting of at least two types of muscle fibers. Therefore, we must pay tribute to the scientists who have devoted themselves to the study of muscle fibers. And here's what they found out...

Appointment of muscle fibers

The question naturally arises, what else is the difference between white and red muscle fibers? During numerous experiments, it was noticed that red fibers contract more slowly, and white fibers faster. Therefore, muscles consisting of red fibers began to be called slow muscles, and those consisting of white fibers were called fast muscles. Now the picture is gradually beginning to clear up, but why does our body need all this?

Probably, nature failed to invent a universal muscle, and she decided to make two main types of muscles, but with a narrow focus of action: fast (white) muscle fibers and slow (red) muscle fibers.

Types of muscle fibers: Fast (white) muscle fibers.

In cases where you need to do a lot of work and very quickly - muscles with white fibers come into play. Because they can quickly contract and give tremendous explosive strength and power, for example, professional sprinters who run a hundred meters in less than 10 seconds ... But they cannot work (shrink) in this mode for a long time, because:

First of all- energy reserves are not eternal and they are enough for just a couple of minutes of intensive work.

Secondly- to restore energy reserves in the muscles - it takes time (from 2 to 5 minutes) to restore the reserves of ATP molecules (the main energy unit in a living body) and creatine phosphate (you will learn about it below). Now you begin to understand why weightlifters rest 1-2 minutes between sets.

And thirdly- with each repetition (muscle contraction), in the process of reactions to generate energy - decay products (lactic acid) are formed, which begins to "burn" the muscles more and more, and as a result of pain and lack of strength (energy) - their work stops .

The energy system of fast fibers is practically directed to anaerobic glycolysis (without oxygen). Why practically? Yes, because it exists. two subtypes of fast fibers: 2A and 2B. 2A is a transitional type of fiber that contracts rapidly, has great strength and uses both aerobic glycolysis (with the participation of oxygen: oxidation of carbohydrates and fats) and anaerobic glycolysis (without the participation of oxygen) as energy. 2B are already pure fast fibers that contract VERY quickly, have tremendous explosive strength and power, and anaerobic glycolysis (without oxygen) is required to replenish their energy.

Types of muscle fibers: Slow (red) muscle fibers.

But when it is necessary to perform a very large amount of work, but not so quickly, over a long period of time, then slow fibers take over. Because they are more enduring, as they use aerobic glycolysis (with the participation of oxygen), but do not have such strength, power and speed as fast muscle fibers. For example, slow fibers are needed by marathon runners who need very good endurance.

However, if everything was clear before, now one cannot do without special terms.

Basics and terms

To understand how each muscle works with white (fast) fibers or with red (slow) fibers, we will have to look into each of them. It is clear that no mechanism will work without replenishment of energy. The same applies to the biological mechanism, that is, a living being. Therefore, in order for the muscle to contract and do the work, it will need to take energy from somewhere.

Red fibers It's no coincidence that they have this color. Since they have a huge amount of myoglobin and a huge network of very thin vessels, or they are also called capillaries. Through the capillaries, oxygen enters the fibers with blood. And myoglobin directly transports this oxygen inside the fiber itself to the mitochondria (chemical stations), where the process of fat oxidation occurs with the release of energy for muscle work. Therefore, the more oxygen enters the blood, the longer the slow fibers work, provided that the load is not very intense.

myoglobin- This is a pigment protein, red in color, which stores, and then delivers oxygen inside the muscle fiber to the mitochondria.

Mitochondria is an organoid whose function is to synthesize the ATP molecule (the main energy unit).

White fibers, have this color due to the small amount of myoglobin and capillaries in them. The energy of white fibers of the subtype 2A (we have already mentioned them above) is aimed at both anaerobic glycolysis (without oxygen) and aerobic glycolysis - oxidation (with the participation of oxygen). But the white fibers of subtype 2B receive energy only from anaerobic glycolysis (without the participation of oxygen). Let me remind you that in red and white fibers, energy synthesis processes occur directly in mitochondria.

All about the work of red fibers

It is believed (it was believed) that red fibers (RMF), in contrast to white fibers (BMW), have very low hypertrophy, but in fact this is not the case. Surprised? This is because for a long period of time, scientists thought that MMBs were practically not subject to hypertrophy. But recent studies have proven the opposite when they took a sample of muscle tissue from professional bodybuilders who train both slow (using pumping - a type of training) and fast fibers (progressive weights). But MIM can grow well only under certain conditions, however, this is another voluminous topic.

Red (slow twitch) fibers are designed in such a way that they can receive ATP molecules only from the oxidation reaction (with the participation of oxygen) of fats or carbohydrates (glucose). Therefore, slow fibers can only train when there is enough oxygen in the body. Most often, a good supply of oxygen to the muscles is carried out only with a load of no more than 20-25% of your maximum and at a slow pace (low intensity). The maximum load is the load with which you can perform this or that exercise no more than 1-2 times (repetition). For example, you press a barbell of 100 kilograms only 1-2 times - 100 kg will be your maximum weight (load). So, if you will press 20-25 kg at a slow pace, then such a load will be performed due to slow muscle fibers (SMF).

Thus, red fibers train (work) only at low intensity loads, over a long period of time. This helps to circulate oxygen through the bloodstream. For example, it can be light jogging, lifting light weights, brisk walking, cycling, swimming, and more.

As soon as you increase the load, fast fibers of the subtype - 2A or, in other words, transitional fibers, will start working, but if you increase the load even more, then fast fibers of the subtype - 2B will start working. In this case, another training will begin, which I will talk about a little later.

In the cells of slow-twitch fibers (MMF) there is a pigment protein - myoglobin (which I mentioned a little higher). Its task is to accumulate as much oxygen as possible, so that later at the right time it can be given to the mitochondria for energy. This happens whenever there is not enough oxygen during MMW operation for some reason.

Here is an approximate power supply scheme for MMV:

1. During a prolonged and low-intensity load, for tens of minutes, oxidation reactions of triglycerides (fats) occur in the cells of red fibers. But for this reaction to continue, oxygen is needed...

2. Oxygen is delivered to the cell with the help of capillaries (hemoglobin). But, and if there is little oxygen through the bloodstream (capillaries), then myoglobin comes into play, which begins to release the oxygen stored in it. Thus, as a result of oxidation reactions - MMB cells receive energy (ATP molecules).

3. And yet, the source of triglyceride fatty acids are formed from subcutaneous or internal fat. Therefore, this is why red meat is considered more fatty than white meat.

Eventually: if your work does not require you to be explosive (speed) and load more than 20-25% of the maximum, then in this case, your body (red fibers) can perform the load for a very long time. Since red muscle fibers use aerobic glycolysis (with the participation of oxygen) for energy, which gives a lot of energy (19 times more), unlike anaerobic glycolysis.

All about the work of white fibers

So, we learned almost everything about red fibers. Now let's try to figure out how white fibers work. White fibers contain a small amount of myoglobin and capillaries. Therefore, they look much brighter. For clarity, remember the chicken. Her breast looks white and the meat on her legs is red.

White fibers contract twice as fast as red ones. It is also surprising that they develop strength 10 times more than muscles with red fibers. But they have a significant drawback. With such excellent characteristics, white fibers get tired quickly.

Fatigue accumulates in them due to the fact that they use a completely different principle of obtaining energy. In addition, as you already know, white fibers have two subtypes of fibers, although it is difficult to distinguish them by color.

- Types of muscle fibers: The first subtype - 2B, which uses for energy - anaerobic glycolysis, a process without the participation of oxygen. These fibers work like small batteries. Since after physical activity, when all the energy has been spent (it is enough for no more than 2 minutes), it is renewed (charged), but this recovery occurs only during rest, for 1-2 minutes.

However, as a result of anaerobic glycolysis, lactic acid (a breakdown product) accumulates, which means that the muscle environment becomes acidic, and the fibers begin to “burn”, stopping their work. Therefore, after their recovery (rest 1-2 minutes), they are again ready to perform their function, as they replenished their energy reserves and, in part, got rid of decay products, thanks to the blood flow.

The source of energy for white fibers is glycogen (produced during the breakdown and processing of glucose) and creatine phosphate (the body receives it from protein foods: meat, fish, eggs, cottage cheese and sports supplements). As a result of physical actions, glycogen, splitting, gives glucose, and glucose gives energy (ATP) and lactic acid. As for creatine phosphate, it restores ATP reserves back in muscle fibers, that is, such a cycle is obtained ...

- Muscle fiber types: Second subtype - 2A, which can work up to a certain state without oxygen (anaerobic glycolysis), and then switch and do work for some time, but already using oxygen (aerobic glycolysis) and vice versa. The purpose of these fibers, as you already understood, is that they go from red to white fibers and from white to red, it all depends on the load being performed.

Simplified, you can imagine the work of subtype 2A something like this:

1. At first, red (slow) fibers begin to do the work, using aerobic glycolysis.
2. When the load exceeds 25% of the maximum, then the white intermediate fibers (2A) already come into operation.
3. But if the load grows even more, then the intermediate fibers (2A) pass the baton to the fibers of the 2B subtype.

Here I presented the work of the muscular system in a somewhat simplified way ... In fact, everything is much more complicated. And to imagine that slow and uniform movements will be performed only due to slow fibers, and high-speed movements due to fast ones, is not entirely correct. For example, fast muscle fibers can be included in the work only by complicating the exercise technique, so the work of certain muscle fibers will depend on the applied force, speed and technique.

The system is so well debugged that a person does not even suspect which muscles he is currently involved in. For example, during a strength exercise, as a rule, all types of fibers begin to contract at about the same time. But in order to complete the contraction, the slow red fibers will need between 90 and 140 ml/sec. At the same time, fast fibers will have time to completely contract in just 40 to 90 ml/sec.

And here is a table that will help you visually understand everything that I wrote about

How to determine which fibers are more

If we talk about the average person, then he will have approximately 40 to 45% slow fibers, and the remaining 55 - 60% will be occupied by fast fibers. In general, this approach is justified, but in different parts of the body, these ratios can vary greatly. It all depends on what kind of work a person does most often or what kind of sport he prefers. By the way, in a long-distance runner, the muscles in the legs are almost all made up of red, slow-twitch fibers (MSF). And in weightlifters and sprinters, the muscles in the legs can be almost 80-90% fast twitch fibers (BMW).

What types of fibers will be more or less - will depend on genetics and trainable qualities. However, numerous studies have shown, just like that, do not move from one type to another. Therefore, for this to happen, it is required to develop certain physical skills (train).

1. To get a beautiful body with well-developed muscles, you need to train all types of muscle fibers, which is what some professional bodybuilders do. However, it is impossible to achieve the maximum result in all physical qualities (speed, strength, endurance, etc.), since the body adjusts its energy systems to a certain trained quality. Therefore, it is not possible to achieve maximum strength and endurance at the same time.
2. Now it becomes clear why it is necessary in training aimed at maximum power (weightlifting) and explosive strength (sprint) to give all the best in the interval from 10 to 60 seconds. Since glycogen and creatine phosphate is only enough for 2 minutes. And after that, you need a rest of 1-2 minutes to replenish energy in the BMW, otherwise the MMV will start working or the pain will be so strong due to lactic acid that you yourself will stop working.
3. So, in order for the red fibers to work, you need a load of no more than 25% of your maximum, but at a low-intensity pace. Low-intensity exercise is very well defined by the heart rate (HR), which should be 60-70% of your maximum. You can calculate the pulse like this: age minus 220 and find 60-70% of the resulting number, this will be your range.
4. Who wants to lose weight - it is very good to train red fibers, as they burn fat perfectly. But do not forget the load should be low-intensity and long, more than 40 minutes.

Essential remark

My story is coming to an end about what types and types of muscle fibers are in our body. Now you have a complete understanding of how certain workouts affect muscle fibers, and how you yourself can influence them. It only remains for me to make one very important remark to help beginners and experienced athletes train even more effectively.

Don't chase big weights. There are many different exercises that help to achieve the desired effect only by requiring a certain body position or posture (exercise technique) to perform them. Therefore, do not try to lift more weight, but try to complicate the technique itself, thereby feeling the working muscles and pumping them even more.

Exercise, eat right and get better - good luck to you.

Hello, dear readers and subscribers of the Pro Tvoi Sport blog. Do you know what red and white muscle fibers are? And how do they differ? I think after reading this material, you will be able to more accurately select the nature of the loads for yourself and adjust your own training. The article, in fact, describes the difference between these fibers and their role. I will also briefly talk about ways to train with a predominant type of fiber.

We all eat chicken, don't we? Have you noticed how meat from the brisket differs from the meat from the thighs? It has a different color, different "companions" (the presence or absence of a fatty layer), and indeed - meat is different for meat. Remember what I just said about chicken meat.

White and red fibers - basic

Despite the fact that these two types of fibers are diametrically opposed, they always work in conjunction, replacing each other.

For example, you train in the gym and started lifting a heavy barbell (no matter how), which you cannot lift more than 2-3 times in one approach (set) in your training. In this case, the blow is taken by the white fibers responsible for the physical work in an explosive style. That is, you can lift heavy weight, but not for long.

Second example: You have significantly dropped the weight from the bar and began to lift it again. Now you feel ready to do up to 20 reps, and you think you can do even more. In this case, red muscle fibers work, allowing the body to do long-term work. After all, doing 3 repetitions and 20 is a big difference in time.

Third example. You have hung on the bar about three-quarters of the weight that you can lift at one time (no more) - this is 75%. In the performed exercise, you can do 10-12 repetitions. I will say that in the first weight lifts, white fibers are actively working, at the end of the exercise, white fibers are significantly weakened (we feel tired, but we can continue to work), and red ones are just starting their work. That's what I was talking about - they replace each other.

Below I will describe in more detail why this is the case.

If these two types are given specific characteristics, then white is strength, red is endurance.

If you think, as I did in my time, that there are only two types of fibers, then you are mistaken. There is also an intermediate type that contains the characteristics of the other two types. He can be both strong and resilient at the same time.

By the way, did you know that the amount of certain fibers is not constant in our body? I bring to your attention, friends, that a certain type of training (if you train systematically for a long time) can change the ratio of fibers: today, reds predominate, and six months later, whites. This means that you were hardy, but after training for six months, you became strong.

What exactly are different?

The physiology of our body is such that the difference between the fibers is manifested in everything from color to the way we eat.

We all know that muscles need nutrition. During physical work, white fibers use glycogen (carbohydrates - glucose, sugar, if you like) and creatine. I will not go into the details of the entire process of glycolysis, but I will say that muscles can use up their glycogen and creatine stores very quickly. That is why we can lift a very large weight, but not for long - all the reserves go into the firebox to lift the weight.

But stocks spent quickly are also quickly restored after work is completed, although not to the full extent. This explains why, after resting between sets, we are able to do a few more sets of the exercise, although performance decreases over time.

Red fibers feed on fat: with the help of oxygen (oxidation), they break down adipose tissue, using it as fuel. Now remember what happens when you run. You actively breathe (oxygen I mentioned), you actively lose weight if you run enough (fat breakdown I mentioned). This description is based on the work and nutrition of red muscle fibers.

I can say that whites predominate in the upper part of the body, and reds in the lower part. Physiology is such that the legs must be strong enough, because we constantly walk or stand. Therefore, there are more reds in the legs. Although, we are all unique, and someone may be the opposite.

For example, sprinters. They don't need to run long, they need to run fast, but for a short distance. Naturally, under the influence of special training, the sprinter's legs will become more white, and less red (as unnecessary). Also, the muscles of the lower back and abs are also rich in red fibers to keep the body in the right position for a long time, and not “turn off” when they get tired.

At the same time, the muscles of the arms, chest and upper back are rich in white fibers, by swinging which you increase the muscles of the torso. But again, I repeat: the body can adapt to conditions and change the nature of the fibers in one or another part of the body, or even throughout the body.

How to train?

Training white fibers is an increase in the volume of fibers due to density and an increase due to reserves of energy sources (the more glycogen and creatine in the muscles, the larger they become). Therefore, if you gain mass, increase strength, but at the same time do not often resort to cardio training, then I am sure that “white color” prevails in you.

Your task is to constantly change the load, either working with submaximal and maximum weights (1-3 times per approach), then with medium and light ones (from 8 to 15 repetitions in one approach). This principle ensures constant muscle growth, but you should not “go in cycles” only in protein nutrition, fast carbohydrates must be present, you yourself saw this.

At the same time, red fiber training is endurance work. Whether it's running or working with free weights with a fifty percent load (during drying) - all this stimulates the development of precisely the "red color".

Do you want to dry off? Then you need to always do at least 15 repetitions in one set, 6-8 sets in each exercise, or run for at least 45 minutes. Only under such conditions can you lose weight and make yourself unrealistically functionally hardy.

I have a lot more to say about this topic, but too much information in one article is bad. Therefore, ask your questions. Well, if you liked the material, then tell your friends about it on social networks and subscribe to blog updates. Be strong!

Sincerely, Vladimir Manerov

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Muscle fiber (myocyte) - the main structural and functional unit of somatic muscle tissue; the third stage and the result of histogenesis. The length of a muscle fiber often coincides with the length of the muscle of which it is a part.

The main classifications of muscle fibers:

• White and red muscle fibers;
• Fast and slow muscle fibers;
• Glycolytic, intermediate and oxidative muscle fibers;
• High and low threshold muscle fibers.

White and red muscle fibers.

The first classification is by color. This is a classification based on the presence of myoglobin pigment in the sarcoplasm of the muscle fiber. Myoglobin is red in color and is involved in the transport of oxygen to the muscle cell. The more oxygen the cell needs, the more myoglobin enters - the fiber is more red. When there is less oxygen, the fiber is lighter, which makes it white. Also, red muscle fibers have more mitochondria than white ones, due to the high oxygen consumption.

White muscle fibers:

• Myoglobin is low.
• Mitochondria are few.
• Oxygen consumption is low.

Red muscle fibers:

• Myoglobin - a lot.
• Mitochondria are many.
• Oxygen consumption is high.

Fast and slow muscle fibers.

The second classification is according to the speed of contraction. Fast and slow muscle fibers are classified according to the rate of contraction and the activity of the ATPase enzyme. The enzyme ATP-ase is involved in the formation of ATP and, accordingly, in muscle contraction. When the more active the enzyme, the faster ATP is synthesized and the muscle is ready to contract again.

Fast muscle fibers:

• The rate of contraction of the muscle fiber is higher.
• The activity of the enzyme ATPase is higher.

Slow muscle fibers:

• The rate of contraction of the muscle fiber is slower.
• The activity of the enzyme ATPase is low.

Glycolytic, intermediate and oxidative muscle fibers.

The third classification is for energy supply. Muscle fibers use fatty acids (fats) and glucose (carbohydrates) for energy. Fatty acids are converted by the body into ATP through oxidation. Glucose is also converted into ATP by anaerobic and aerobic glycolysis. Therefore, there are three types of different muscle fibers in the body, which mainly use one of the types of energy supply.

Oxidative muscle fibers (OMF):

• The main source of energy is fatty acids.
• Energy supply - oxidation.

Intermediate muscle fibers (IMF):

• The main source of energy is fatty acids, glucose.
• Energy supply - oxidation, glycolysis.
• The number of mitochondria is an average number.

Glycolytic muscle fibers (GMF):

• The main source of energy is glucose.
• Energy supply - glycolysis, mainly anaerobic.

Separately, we should talk about PMV. This type of muscle fibers adapts very well to the load, unlike OMV and GMV. With prolonged training, these muscle fibers may acquire more signs of OMV or GMV. For example, if you train endurance (running marathons and the like), in this case, almost all PMAs will become OMF, due to an increase in the number of mitochondria. During strength training, the MPV is rebuilt into the GMV, adapting to the corresponding type of training.

High and low threshold muscle fibers.

The fourth classification is according to the excitability threshold of motor units (MU). A motor unit consists of a motor neuron and a muscle fiber. Muscle contraction occurs under the influence of nerve impulses that conduct nerve cells from the brain to the muscle, giving it the command to contract.

High threshold muscle fibers:

• The threshold of excitability is high (they decrease with a strong impulse, when it is very difficult).
• The speed of nerve impulse transmission is high.
• Axon with myelin sheath.

Low threshold muscle fibers:

• The excitability threshold is low (they decrease with a weak impulse.).
• The speed of transmission of the nerve impulse is low.

Combining classifications.

White fast high-threshold glycolytic muscle fibers (hereinafter referred to as HCMF):

• White color.
• The speed is great. The main energy supply is anaerobic glycolysis.
• The threshold of excitability is high.
• Axon - with myelin sheath.
• The number of mitochondria is small. The number of muscle fibers in the body is determined by genetics (this is not a fact, since now there is a theory according to which motor neuron myelination occurs from a training load).

This type of muscle fibers, in people who are not involved in sports, almost never takes part in muscle contraction. These muscle fibers are activated only under extreme conditions for a very short time. In athletes involved in anaerobic sports, these muscle fibers are actively involved in contraction at peak loads (90-100% of the RM, usually 1-3 repetitions).

White fast glycolytic muscle fibers (hereinafter referred to as GMF):

• White color.
• The speed is great.
• The main energy supply is anaerobic glycolysis, partially aerobic.
• The threshold of excitability is medium (below GMW, above PMW).
• Axon without myelin sheath.
• The number of mitochondria is small.
• The number of muscle fibers in the body is different (PMV turns into GMV during strength training).
• GMF is the basis of all muscle mass. Even if a person is dominated by OMF in quantity, the entire main volume of the muscle will be due to the GMF, since these muscle fibers are much larger in the volume of all the others. GMV are included in the work in almost all strength exercises.

Intermediate (can be either white or red) muscle fibers (hereinafter PMF).

• Color - white, red.
• Contraction speed - low, high (some studies confirm that the activity of the ATPase enzyme cannot change with training, therefore it is possible that the PMAs that turned into PMAs remain slow).
• The main energy supply is anaerobic glycolysis, aerobic glycolysis, oxidation.
• The threshold of excitability is medium (below VGMV, GMV, above OMV).
• The number of mitochondria is average (depends on the fitness of the person).
• The number of muscle fibers in the body is different (many in untrained people, in trained PMAs turn into GMF or OMF).

PMV is something averaged between GMV and OMV, they use energy supply, both OMV and UMV. The special ability of these muscle fibers is the acquisition of signs of OMV or GMF, depending on the load. If there is an anaerobic load and more glycolysis is needed, PMF are converted into HMF. If a person receives an aerobic load, PMV turns into OMV.

Red slow oxidative muscle fibers (hereinafter referred to as OMF):

• Color - red.
• The contraction rate is low.
• The main energy supply is oxidation.
• Excitability threshold is low.
• Axon without myelin sheath.
• The number of mitochondria is many.
• The number of muscle fibers is different, intermediate muscle fibers are converted into OMF during endurance training.

Approximately 40% of the mass of the human body is accounted for by muscles. Each of the more than 600 muscles is necessary for us to perform vital functions: eating, breathing, walking, etc. In order for the muscles to be strong, they need to be trained. And to determine the correct type of training, you need to know that all the muscles of our body consist of two main types of muscle fibers, the features of which the site will tell about in this article.

Different muscle fibers - different functions

Skeletal muscles are made up of two main types of fibers:

1. Type I fibers are responsible for endurance, type II fibers (fast, glycolytic, white) - for strength and speed.
2. Type II fibers begin to work when physical activity requires more than 25% of the maximum force to be used.

In most people, the ratio of muscle fiber types is approximately the same, and it is determined genetically. However, fast fibers are larger than slow fibers and have greater growth potential.

Genes determine three important factors in relation to muscle:

1. The maximum number of fibers.
2. The ratio of muscle fiber types.
3. The shape of fully engaged muscles.

The ratio of muscle fiber types is determined genetically, and it is possible to identify the dominant type only through invasive muscle biopsy.

• features and exercises for training type I fibers;
• features and exercises for type II training.

Muscle fibers of the slow (I) type: features of the structure and work

What you need to know about type I (slow) muscle fibers:

• they contain mitochondria that use oxygen to produce the ATP needed for muscle contraction;
• they are called red muscle fibers because they contain more myoglobin (oxygen-binding protein), which makes them darker;
• since slow muscle fibers can provide themselves with energy, they can withstand small force loads for a long time, but are not able to provide significant force;
• this type of muscle fibers is characterized by a low activation threshold, i.e. they are the first to be activated during muscle contraction; if they are not able to generate enough force to perform a certain action, fast muscle fibers are activated;
• the tonic muscles responsible for posture have a higher density of red fibers;
• static endurance exercise can increase mitochondrial density, which increases the efficiency of using oxygen to produce ATP.

What exercises are suitable for training slow-type muscle fibers

The characteristics of slow muscle fibers and the features of their functioning allow us to determine the types of exercises that increase their aerobic activity. These exercises are:

• isometric exercises (example: plank), which keep slow-type muscle fibers in a contracted state for a long period of time - due to this, the ability of such fibers to use oxygen for energy production increases;
• slow strength exercises with low weight, but more than 15 repetitions, in which aerobic metabolism is activated;
• circuit training, in which one exercise replaces another almost without interruption;
• exercises with a body weight and a large number of repetitions also increase the efficiency of the work of slow fibers;
• when doing exercises with your own or light weight to train slow muscle fibers, it is better to reduce the interval between sets to about 30 seconds.

For slow muscle fibers, slow exercises, multiple repetitions and small loads are suitable.

Muscle fibers of the fast (II) type: features of the structure and functioning

Muscle fibers of type II (white) are divided into fast fibers of type IIa and IIb:

• muscle fibers IIa (fast oxidative-glycolytic) use oxygen to convert glycogen to ATP;
• muscle fibers IIb (glycolytic) use ATP from muscle cells to generate energy;
• fast muscle fibers are characterized by a high activation threshold, i.e. they are activated only when slow fibers are not able to provide the required amount of force;
• type II fibers reach peak strength faster and can develop significantly more force than type I fibers;
• fast fibers are called white because they contain few capillaries;
• white fibers “get tired” faster;
• phasic muscles responsible for movement are characterized by a high density of fast fibers;
• Fast fibers are responsible for the size and definition of certain muscles.

What exercises are suitable for training fast-type muscle fibers

Based on the characteristics of fast muscle fibers, it can be concluded that exercises for the development of explosive strength and strength training are suitable for their training, namely:

• strength training with more weight stimulates motor units and activates more muscle fibers; the greater the weight, the more fast fibers are used to lift it;
• explosive movements with weights or using your own body weight are a great way to train white muscle fibers;
• fast muscle fibers get tired quickly, therefore, to achieve maximum efficiency during the exercise, it is recommended to limit the number of repetitions to 2-6;
• since this type of muscle fiber uses energy quickly, they require a longer rest period (at least 60-90 seconds between exercises) to recover.

It is fast fibers that determine the size of the muscles, and explosive movements with weights are best suited for training them.

Understanding how the body adapts to stress allows you to develop the most effective training program that meets your individual needs.

Hey! What tricks will the body go to to save energy in order to increase our survival rate. Although, judging by how the population is growing, sometimes you think that it would be better if he did not do this. Ha ha. But seriously, everything in our body is balanced and optimized. The body will never do what is not beneficial to it.

A word about saving energy

As I said, the body does everything in order to:

1. Save as much energy as possible(which is why we store excess energy as fat).
2. Spend as LESS energy as possible in any job(that's why we are all lazy by nature).

This allowed us to survive for TENS OF THOUSANDS of years. Our ancestors in one week could enjoy the meat of a slaughtered animal, and then for two or more weeks they practically starve, eating only roots (agriculture appeared later).

Therefore, our body WAS TEACHED that in order to survive in the harsh conditions of natural selection (predators, diseases, hunger, etc.) it is NECESSARY to SAVE THE ENERGY RECEIVED!

It does this whenever possible, for example:

• Nutrient storage system (we store excess food in fat, and do not remove it from the body);
• Muscular adaptation (muscles will not grow without increasing the load, i.e. without a HARD need to warn yourself from danger);
• Hair on the body, calluses on the hands from constant work, sunburn (even this is done to save energy, because this is also a forced adaptation to external influences);

The body adapts ONLY WHEN NECESSARY, such as: “It is better to grow body hair than to freeze from the cold”, “It is better to grow calluses on your hands than to get blood poisoning and die”, etc. It will not do this if you do not need! It SAVE ENERGY!

What can I say EVERYTHING IN OUR BODY IS MADE TO SURVIVE BETTER IN THE ENVIRONMENT! If the body can save energy somewhere, it will do it! Therefore, it is always more convenient for us to walk than to run; stand than go; sit than stand; lie than sit, etc.

As you probably already understood, LAZINESS- this is also an ADAPTATION MECHANISM of the body, to save energy.

It was in order to save energy that our body created another amazing mechanism - different types of muscle fibers.

In order to save energy, the muscle fibers in our body are heterogeneous.

What is the point of dividing our muscles into different types of muscle fibers? VERY BIG!

Look, as a rule, in life we ​​have different physical activity according to the nature of the load, namely:

1. Very heavy (for example, you need to move a very heavy piano).
2. Medium in severity, high in volume (for example, to transfer many, medium in severity, sacks of potatoes).
3. Easy (long, monotonous run).

Is it beneficial for our body, for example, to use the ENTIRE HUGE MUSCLE MASS OF THE LEGS for a light load? Naturally, NO!

It is for this purpose that our body created “different workers” to perform work of a different nature.

1. Fast muscle fibers (BMF).
2. Slow muscle fibers (SMF).

But! There are also fibers that are designed to do EXTREMELY HARD WORK, namely HIGH THRESHOLD fast muscle fibers (HFMF).

Those. we get three main types of muscle fibers:

To better imagine the situation, why the body needed such transformations, then imagine that our ancestors gathered to hunt.

Here they are slowly moving through the forest and, in their opinion, are in complete control of the situation. And SUDDENLY a PREDATOR jumps out of the bushes on one of them - a SABER-TOOTH TIGER!

The man is SCARED TO DEATH and in a split second he jumps to the side so as not to die. At this point, HIGH THRESHOLD FAST MUSCLE FIBERS, which were created for extreme work and for instant response, worked.

But the predator does not give up and starts to run after the Cro-Magnon man. Here, FAST MUSCLE FIBERS come into play, which allow you to gain fast speed in a short time!

But now, the predator does not give up and still pursues the unfortunate bare-assed hunter. After a certain time, the hunter's body understands that it will take a long time to run and turns off fast muscle fibers, while connecting SLOW MUSCLE FIBERS to perform monotonous, long work (running).

Well, figs with him, let there be a happy ending. The man ran to the cliff and jumped into a deep river and swam away to his fellow tribesmen.

Things like that guys. Got it? Our body during physical activity does not use all the fibers of the working muscles at once., and uses only those that he needs to perform this SPECIFIC TYPE OF WORK! And all because this way he can save more energy. Part of a muscle uses less energy than the entire muscle! Elementary.

I want to make one reservation. Endurance can be both fast and slow muscle fibers, and fast ones can be both hardy and easily fatigued.

However, for ordinary people involved in sports at an amateur level or not involved in sports at all, things will be that way. MMVs are likely to be more durable than BMWs. they will have much more mitochondria and mitochondrial enzymes.

Mitochondria, in turn, are capable of obtaining “energy” as a result of chemical transformations from the oxygen (respiration) and reagents (fats or pyruvate) at their disposal - the same ATP that provides almost all energy-consuming processes in our body.

Purpose of different types of muscle fibers

Let's take a closer look at the different types of muscle fibers. So:

• High threshold fast muscle fibers (HFMF)– Designed for VERY HARD WORK and FAST WORK with SUB-MAXIMUM weights. They use fast sources of energy for their contraction, which are capable of rapid resynthesis (creatine phosphate and glycolysis). When an athlete lifts a barbell with weight for 1 time, i.e. 1 repeated maximum (RM), then all this is the work of HIGH THRESHOLD BMWs. So that you don’t break yourself, nature has come up with a similar mechanism, a “rapid response team”, if you want. These fibers are very strong and WHITE.
• Fast muscle fibers (BMW)- designed to perform HEAVY and HIGH-VOLUME work with a MODERATE-HEAVY WEIGHT (for 6-12 repetitions). Use for reduction, as well as VBMV, fast sources of energy. These fibers are also called WHITE and are used by all athletes of speed-strength sports (including BB).
• Slow muscle fibers (SMF)- they are designed to perform light, long, monotonous work. Perform SLOW and LIGHT contractions. Therefore, they use slower, but economical sources of energy supply. One of these is the OXIDATION OF FAT WITH THE HELP OF OXYGEN. This gives noticeably more energy than glycolysis, but it takes more time, because. the oxidation reaction is very complex and requires a lot of oxygen, because of which the MMB is called RED MB (because oxygen is carried by hemoglobin, which gives the fibers a red color). These are the fibers that are mainly used by marathon runners, cyclists, etc.

So, is it worth bothering to train other muscle fibers at all?

Do I need to train all muscle fibers?

If you are a beginner bodybuilder, then MOSTLY NOT! Your body is not yet accustomed to the load and has not even learned , designed for such work FAST MUSCLE FIBERS.

BUT! If you have already been in the gym for 2-3 years and have stalled in the results, then training slow muscle fibers can cause very good progress!

It would seem that if a person runs marathons, then it is logical for him to train MMV, and if he works with very heavy weights, then BMW and VBMV. But it's not that simple, friends.

Body-building- a very specific sport, where all means are good to achieve maximum performance (from training different types of muscle fibers and microperiodization to the use of very large doses of pharmacology).

ONE WHOLE IS ALWAYS BIGGER AND STRONGER THAN PART! If we develop all muscle fibers, then it is logical that the muscle will be larger in general.

It used to be thought that there was no point in training MIM. The fact is that when a BIOPSY (a sample of a small part of a muscle) was taken from athletes of Olympic sports (weightlifting, sprinters, javelin throwers, etc.), they noticed that, as a rule, there are many times more fast muscle fibers, than slow ones. Therefore, they said that you need to train fast fibers and "not bathe." Research closed.

But what was the surprise of the guys in white coats when after some time they took samples of muscle tissue from professional bodybuilders! THE NUMBER OF FAST AND SLOW MUSCLE FIBERS WAS THE SAME!

After additional experiments, scientists concluded that SLOW MUSCLE FIBERS ARE SUBJECT TO GROWTH AS WELL AS FAST!

Why are the results of bodybuilders different from the results of other athletes?

difference in purpose. In Olympic sports, they are different. Run faster, push more, throw farther, etc. And in bodybuilding, volumes, proportions and appearance are important.

Therefore, it is important for Olympians to minimize muscle growth, including MMB. They need fast muscle fibers or high-threshold ones in order to make maximum effort at the right time.

Okay, you say, why don't marathon runners who need slow muscle fibers have huge pumped legs? It's all about the method of training MMV, friends.

MMV training method. acidification of the blood

Let's start with a bit of theory. With all the current technical and other progress, we still DO NOT KNOW WHAT EXACTLY STARTS MUSCLE GROWTH!

But what about the progression of loads, stress, anabolic hormones, amino acids, etc., you ask? Yes, and again, yes! Only these are just the FINAL MECHANISMS OF MUSCLE GROWTH.

But we do know for sure that SYNTHESIS OF A NEW PROTEIN IS STARTED THROUGH THE DNA OF THE CELL.

In order for hormones to start protein synthesis, this information must be copied from the DNA of the cell nucleus. And the DNA chain itself, as we know, is twisted from two helices.

To start protein synthesis WE NEED TO REVOLVE THE DNA SPIRAL! How to do it? With the help of HYDROGEN IONS!

Pumping- this is, roughly speaking, the pumping of muscles with blood. But remember what pumping should be, in the classical sense? I will not torment, it must be POWERFUL! Those. approximately 80% of the WORKING WEIGHT!

For example, if you pressed a 100 kg barbell for 6-8 times, then for a pumping workout you need to take 80 kg and perform 12-15 repetitions. Do you understand? This will pump the muscles with blood, but this is not exactly the mode of operation that is aimed at the development of MMV.

Add to this the fact that in pump training, as a rule, the approach is performed at a FAST PACE! And for the fast pace of movement, we have created BMWs.

MMB should be trained with about 50% weight and at a VERY SLOW pace! But more on that later.

Back to the question why long-distance marathon runners don't have large, slow muscle fibers? After all, they train them directly!

There are two factors here:

1. No load progression. Although the load is light and monotonous, it must increase, otherwise the muscles will not make sense to increase.
2. No muscle acidification. Yes, they work for a long time, with a lot of repetitions (thousands of steps), but the BLOOD CIRCULATES FREELY IN THE MUSCLE (in and out), therefore washing away the hydrogen ions. Accordingly, there is no growth reaction.

How to make MIM grow?

Although MMW grow no worse than BMW, but in order to start protein synthesis in muscle fiber (any, even BMW, even MMW), it is necessary to have HYDROGEN IONS that trigger it.

It is easier for fast muscle fibers to achieve this, because. for energy supply they use the ANAEROBIC (oxygen-free) way. Therefore, the blood (the tool for transporting oxygen to the muscles) DOES NOT flush out the HYDROGEN IONS that are needed to trigger muscle growth.

Why is it harder to do this in MMV? Because MMVs use an AEROBIC (oxygen) method of energy supply! This means that blood is needed to transport oxygen. Do you understand? The blood makes it possible to feed on oxygen (delivers it), but WASHES OFF THE HYDROGEN IONS that are needed for growth! Here is a vicious circle for you, which does not allow MMW to grow under normal conditions.

To put it simply, "native" methods of energy supply allow BMW to grow, but do not allow MMV to grow!!! This is why marathon runners have small muscles.

All this is understandable, but how to get out of this vicious circle and pump up our slow muscle fibers to become 2 times bigger?

• Make MMV work;
• Use a different power supply;

Those. a certain load is needed to turn on the MMV, but DO NOT RELEASE BLOOD FROM THE MUSCLE to acidify it!!!

How to do it? PUMP, friends! But in a slightly different way.

Optimal pumping mode

In bodybuilding, a dynamic (fast) mode of exercise is usually used, and relaxation follows after each repetition.

In this mode, the vessels open and allow blood to circulate freely into and out of the muscle. This is bad for the growth of the IIM, as they need HYDROGEN IONS for growth, and the blood washes them away. The muscle does not acidify and MMB do not grow (no increase in strength and mass).

Therefore, the classic pumping regime, i.e. DYNAMIC POWER IS NOT SUITABLE FOR US!

We need to use CONSTANT MUSCLE TENSION! After all, if the muscle is tense, then it does not let blood through. This is good, because this contributes to the accumulation of HYDROGEN IONS in it!

HYPOXIA(no oxygen due to constant voltage) –> ANAEROBIC GLYCOLYSIS(breakdown of glucose without the participation of oxygen) –> Accumulation of HYDROGEN IONS.

Fine. Got it sorted out. Again. The muscle should not let blood through (constant tension), anaerobic glycolysis occurs (no air), so hydrogen ions accumulate (because blood and oxygen do not circulate).

Now let's look at what the conditions for MMB hypertrophy should be.

Practical scheme for MMB hypertrophy

What we need for maximum hypertrophy (“bloat” of muscle cells):

Let's look at this using the example of lifting a barbell for biceps while standing.

For example, your working weight is 30 kg for 10-12 reps, and you lifted 40 kg for 1 rep (40 kg is your 1 RM). PM is a repeated maximum!

How to act?

• First, we select the weight based on our 1RM. We take 30-50% from it, i.e. from 40 kg, it will be 12-20 kg.
• Now, bending our elbows at the elbows, we remember our starting position. ARMS SHOULD NOT EXTEND FULLY during the approach, so as not to let blood through. We work INSIDE the amplitude! Those. we do not reach the upper and lower points. As soon as we feel that the muscle can relax, we stop and move in the opposite direction.
• Raise and lower the barbell VERY SLOWLY! At the expense of 1-2 up and 3-4 down! If possible, even slower! So we use our MMV and turn off the BMW.
• ACHIEVE UNBEARABLE BURNING! This is a very important point. It must be so strong that it is simply not possible to lift this lightest weight again. We reach muscle failure. This will indicate the maximum acidification of the muscle, i.e. about the high content of HYDROGEN IONS. There will be more repetitions than usual, namely 20-30 and the approach will last 30-50 seconds. This is fine!

This is what one approach would look like. How many approaches should be? In theory, VERY MUCH, but we, as you know, so let's look for a solution.

To reduce the burning sensation, we need about 5 minutes, and for it to disappear completely, we need 40-60 minutes.

Therefore, based on the above, it would be optimal to perform such approaches every hour throughout the day. But this will not be convenient for anyone.

I prefer to use the STEP METHOD of muscle acidification. Those. you do 3-4 sets with MINIMUM REST, then rest for 3-4 minutes and repeat 3-4 sets again, so again rest 3-4 minutes and again a series.

Example: You completed a set for biceps in 30 seconds. Rest 20-30 seconds and repeat the second set, now rest 20-30 seconds again and do the third set. Now rest for 3-4, or maybe 5 minutes. And repeat a series of 3 sets with a break of 20-30 seconds. Such "series" can be done from 2 to 5 within one workout.

AN APPROACH(30-50 sec) + REST(20-30 sec) + AN APPROACH(30-50 sec) + REST(20-30 sec) + AN APPROACH(30-50 sec) + REST (3-5 minutes!) … REPEAT SERIES…

By the way, this is convenient because many exercises can be performed at home (push-ups, biceps, triceps, deltas).

conditions for muscle growth

So what does it take to build muscle?

• TRAINING STRESS (destruction)! It is needed in order to promote the production of ANABOLIC HORMONES! Only then will the body turn on the process of growth (anabolism).
• HORMONAL BACKGROUND! We need HORMONES that copy information about protein synthesis from the cell's DNA. It is thanks to them that metabolism (metabolism) shifts towards growth (anabolism). The destruction of protein structures during training causes the body to repair the damage. This healing, just, is called PROTEIN SYNTHESIS.
• HYDROGEN IONS! We have already talked about them quite a lot today. They unwind the DNA helix so that information about protein synthesis becomes available for reading by hormones (steroid-receptor complexes). If there is not enough hydrogen ions that are released in response to the consumption of ATP, then hormones will not be able to read information about protein synthesis and start growth. REMEMBER: HORMONES (steroids) without training stress WILL NOT GIVE RESULT, but TRAINING WITHOUT HORMONES WILL!
• CREATIN PHOSPHATE! Gives energy to the DNA molecule for its rapid work. Also, creatine monohydrate supplementation can help you complete an extra couple of repetitions in a workout. A good thing.
• AMINO ACIDS for growth! In order to grow muscles, you need to have something to grow from! Amino acids are the plastic building blocks for muscle growth.

Yes, protein (amino acids) is very important! But more in terms of DIET (deficiency of simple carbohydrates). Imagine when you are losing weight, i.e. if you don't eat carbs and exercise, then there is VERY little glycogen in your muscles, which means you have to use amino acids as energy (an expensive food source). If you drink extra during training and after the amino acid, then you will save more muscle.

This is not beneficial for sports nutrition manufacturers, because. PROTEIN IS EXPENSIVE and you can get MORE from its sale! But I think it is. CARBOHYDRATES ARE MORE IMPORTANT than protein, especially in terms of gaining muscle mass, because. give energy to your muscles.

The fact is that after a workout, your body DOES NOT EVEN THINK about growing muscle, because. it has depleted the energy reserves! He needs to fill them up! That is why the next two days after training, your body replenishes energy reserves and does not even think about growth. And contractile proteins continue to break down due to enzymes - PROTEIN KINASES! Only after 2 days the body starts recovery and, as they usually write, recovers in 7 days. But in fact, even more. Usually in 10-14 days.

To summarize:

1. TRAINING STRESS(destruction).
2. HORMONAL BACKGROUND(starting synthesis from DNA).
3. HYDROGEN IONS(unwinding the DNA helix for hormones).
4. CREATIN PHOSPHATE + CARBOHYDRATES(energy supply).
5. AMINO ACIDS(building material for plastic structures).

This applies to ANY muscle fibers (MMV, BMW, VBMV). The only difference is that it is more difficult for the MMW to maintain the desired concentration of hydrogen ions, so it is necessary to perform the exercises in a certain way, as we discussed earlier in this article.

Is it possible to combine MMV and BMW training?

Can. I'll say more. That's exactly what I did in the army. I remember that once I trained my hands in such a way that I could not fasten my tunic in the morning, my colleagues helped me, because. they hurt unbearably! That's what it means, never coached MMV.

There are several basic rules:

• MMV ALWAYS TRAIN AFTER BMW(if you train them in one workout).
• MMV RECOVERY LESS(2-3 days, i.e. already on the third day you can train again).
• BMW + 1-2 rest days + MMV(if you train at different workouts).

Sample Workout #1 (ALTERNATE WEEKS):

• BMW week (80-90% of 1RM, 6-8 reps, fast pace, failure);
• week MMV (30-50% of 1 RM, 30-50 seconds approach, constant voltage, there is a failure);
• recovery week (50%, 8-12 reps, no failure);

An example of a training program No. 2 (BMW + MMV in one training session):

• Week BMW + MMV;
• Recovery week (or very light workouts with 50% weight NOT TO FAILURE);

OK. But how to combine in practice the training of MMV and BMW?

An example of a combination (BMW + MMV in one training session):

1. bmw- Incline bench press: 4 sets (80 kg x 6-12).
2. bmw- Incline Dumbbell Press: 4 sets (30 kg (1 dumbbell) x 6-12).
3. bmw– Wiring dumbbells lying on a bench: 4 sets (20 kg (1 dumbbell) x 8-12).
4. MMB - Bench press on an incline bench: 2-3 x ((30 kg = 30-50 sec approach + 20-30 sec rest) x 3 sets + 3-5 min rest + REPEAT SERIES ...).
5. IIM– Incline Dumbbell Press: 2-3 x ((10-15 kg (1 dumbbell) = 30-50 seconds set + 20-30 seconds rest) x 3 sets + rest 3-5 minutes + REPEAT SERIES ...).

See what's funny? BMW we always swing at the beginning, before the MMV! MMV ALWAYS AT THE END! IN NO EVENT SHOULD BE REPLACED!

If we trained two muscle groups in one workout, for example, CHEST + ARMS, then we would first need to train BMW CHEST, then BMW ARMS, and only AFTER MMB CHEST + MMB ARMS. Just as you can see, WE TRAIN LARGE MUSCLE GROUPS FIRST (legs, back, chest), and only then SMALL (deltas, arms, calves).

RIGHT= BMW Chest + BMW Arms + MMV Chest + MMV Arms.

NOT RIGHT = BMW Chest + MMV Chest + BMW Arms + MMV Arms.

NOT RIGHT= BMW Arms + MMV Arms + BMW Chest + MMV Chest.

On this, perhaps, I will finish the article. If you are a beginner, then you DON'T NEED this yet, but if you are already an experienced athlete who has been training for two years and has stalled in the results, then MMB training can be a very good help in reaching new horizons in muscle growth.

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With respect and best wishes, !