Skeletal muscle fibers are subdivided into fast and slow. The speed of muscle contraction is different and depends on their function. For example, the gastrocnemius muscle contracts rapidly, and the eye muscle contracts even faster.

Figure: Types of muscle fibers

IN fast muscle fibers the sarcoplasmic reticulum is more developed, which contributes to the rapid release of calcium ions. They are called white muscle fibers.

Slow muscles are built from smaller fibers and are called red because of their reddish coloration due to their high myoglobin content.

Figure: Fast and slow muscle fibers

Table. Characterization of the three types of skeletal muscle fibers

Indicator	Slow oxidative fibers	Fast oxidative fibers	Fast glycolytic fibers
The main source of ATP formation		Oxidative phosphorylation	Glycolysis
Mitochondria
Capillaries
	High (red muscles)	High (red muscles)	Low (white muscles)
Glycolysis enzyme activity		Intermediate
		Intermediate
Fatigue rate	Slow	Intermediate
Myosin ATPase Activity
Shortening speed	Slow
Fiber diameter
Motor unit size
Motor axon diameter

Muscle strength

Muscle strength is determined by the maximum amount of load that it can lift, or by the maximum force (tension) that it can develop under isometric conditions.

Single muscle fiber is able to develop an effort of 100-200 mg. There are approximately 15-30 million fibers in the body. If they acted in parallel in one direction and at the same time, they could create a voltage of 20-30 tons.

Muscle strength depends on a number of morphological, functional, physiological and physical factors.

Muscle strength calculation

Muscle strength increases with an increase in the area of \u200b\u200btheir geometric and physiological cross-section. The physiological cross-section of a muscle is the sum of the cross-sections of all muscle fibers along a line drawn perpendicular to the course of the muscle fibers.

In a muscle with a parallel course of fibers (for example, a sartorius muscle), the areas of the geometric and physiological cross-sections are equal. In muscles with an oblique course of fibers (intercostal), the physiological section area is larger than the geometric area and this contributes to an increase in muscle strength. The physiological section and strength increase even more in muscles with a feathery arrangement of muscle fibers, which is observed in most muscles of the body.

In order to be able to compare the strength of muscle fibers in muscles with different histological structures, the concept of absolute muscle strength is used.

Absolute muscle strength - the maximum force developed by the muscle, in terms of 1 cm 2 of the physiological cross-section. The absolute strength of the biceps is 11.9 kg / cm 2, the triceps brachii muscle is 16.8, the gastrocnemius 5.9, the smooth muscle is 1 kg / cm 2.

where A ms - muscle strength (kg / cm 2); P is the maximum load that the muscle can lift (kg); S is the physiological cross-sectional area of \u200b\u200bthe muscle (cm 2).

Strength and speed of contraction, muscle fatigue depends on the percentage of different types of motor units included in this muscle. The ratio of different types of motor units in the same muscle in different people not the same.

The following types of motor units are distinguished:

• slow, tireless (red), they develop a small force of contraction, but can be in a state of tonic tension for a long time without signs of fatigue;
• fast, easily fatigued (white), their fibers develop great force of contraction;
• fast, relatively resistant to fatigue, developing a relatively large force of contraction.

In different people, the ratio of the number of slow and fast motor units in the same muscle is determined genetically and can vary significantly. The greater the percentage of slow fibers in a person's muscles, the more it is adapted to long-term, but low-power work. Individuals with a high content of fast strong motor units in their muscles are capable of developing great strength, but are prone to rapid fatigue. However, it should be borne in mind that fatigue also depends on many other factors.

Muscle strength increases at its moderate stretch. One of the explanations for this property of muscles is that with a moderate stretching of the sarcomere (up to 2.2 μm), the likelihood of the formation of more bonds between actin and myosin increases.

Figure: The relationship between the force of contraction and the length of the sarcomere

Figure: The relationship between muscle strength and length

Muscle strength depends on the frequency of nerve impulsessent to the muscle, synchronization of the contraction of a large number of motor units, preferential involvement in the contraction of one or another type of motor units.

The strength of the contractions increases:

• when more motor units are involved in the reduction process;
• when synchronizing the contraction of motor units;
• when more white motor units are involved in the contraction process.

If it is necessary to develop a small effort, first the slow, indefatigable motor units are activated, then the fast, resistant to fatigue. If it is necessary to develop more than 20-25% of the maximum strength, then fast, easily fatigued motor units are involved in the contraction.

With a voltage of up to 75% of the maximum possible, almost all motor units are activated and a further increase in strength occurs due to an increase in the frequency of impulses sent to muscle fibers.

With weak contractions, the frequency of sending nerve impulses along the axons of motoneurons is 5-10 pulses / s, and with a large force of contraction it can reach up to 50 pulses / s.

In childhood, the increase in strength is mainly due to an increase in the thickness of muscle fibers, which is associated with an increase in the number of myofibrils in them. The increase in the number of fibers is insignificant.

When training muscles in adults, an increase in their strength is associated with an increase in myofibrils, and an increase in their endurance is due to an increase in the number of mitochondria and the production of ATP due to aerobic processes.

There is a relationship between the strength and speed of muscle contraction. The greater its length, the greater the rate of muscle contraction (due to the summation of the contractile effects of sarcomeres). It decreases with increasing load. A heavy load can only be lifted when driving slowly. The maximum speed of contraction achieved by contraction of human muscles is about 8 m / s.

Muscle power equal to the product of muscle strength and speed of shortening. Maximum power is achieved at an average rate of muscle contraction. For the arm muscles, the maximum power (200 W) is achieved at a contraction speed of 2.5 m / s.

Muscle contraction and power decrease as fatigue develops.

Thin muscle fibers form each skeletal muscle. Their thickness is only about 0.05-0.11 mm, and their length reaches 15 cm. The muscle fibers of the striated muscle tissue are collected in bundles, which include 10-50 fibers. These bundles are surrounded by connective tissue (fascia).

The muscle itself is also surrounded by a fascia. Muscle fibers make up about 85-90% of its volume. The remainder is the nerves and blood vessels that run between them. At the ends, the muscle fibers of the striated muscle tissue gradually merge into tendons. The latter are attached to the bones.

Mitochondria and myofibrils in muscles

Consider the structure of muscle fibers. In the cytoplasm (sarcoplasm) it contains a large number of mitochondria. They play the role of power plants in which metabolism occurs and energy-rich substances are accumulated, as well as those that are needed to meet energy needs. Any muscle cell contains several thousand mitochondria. They occupy about 30-35% of its total mass.

The structure of the muscle fiber is such that a chain of mitochondria aligns along the myofibrils. These are fine threads that contract and relax our muscles. Usually in one cell there are several tens of myofibrils, while the length of each can reach several centimeters. If we add up the mass of all myofibrils that make up the muscle cell, then its percentage of the total mass will be about 50%. The thickness of the fiber, therefore, depends primarily on the number of myofibrils in it, as well as on their transverse structure. In turn, myofibrils are composed of a large number of tiny sarcomeres.

Cross-striped fibers are characteristic of the muscle tissues of both women and men. However, their structure is somewhat different depending on the gender. Based on the results of muscle biopsy, it was concluded that the percentage of myofibrils in the muscle fibers of women is lower than in men. This applies even to high-level athletes.

By the way, it itself is distributed unequally throughout the body in women and men. Most of it in women is in the lower body. In the upper, the volumes of the muscles are small, and they themselves are small and often completely untrained.

Red fibers

Depending on fatigue, histochemical coloration and contractile properties, muscle fibers are divided into the following two groups: white and red. The red ones are slow fibers with a small diameter. In order to get energy, they also use carbohydrates (such a system of energy production is called aerobic). These fibers are also referred to as slow or slow twitch fibers. They are sometimes referred to as Type 1 fibers.

Why red fibers got this name

They are called red because they have a red histochemical color. This is due to the fact that these fibers contain a lot of myoglobin. Myoglobin is a special pigment protein that is red in color. Its function is that it delivers oxygen deep into the muscle fiber from the blood capillaries.

Features of red fibers

Slow muscle fibers have many mitochondria. They carry out the oxidation process, which is necessary to obtain energy. The red fibers are surrounded by a large network of capillaries. They are needed to deliver a large volume of oxygen along with the blood.

Slow muscle fibers are well adapted to the implementation of the aerobic energy production system. The force of their contractions is comparatively small. The rate at which they consume energy is sufficient for only aerobic metabolism to get by. Red fibers are great for non-intense and prolonged work such as walking and light jogging, distance swimming, aerobics, etc.

The contraction of the muscle fiber allows the execution of movements that do not require much effort. It also supports the posture. These striated fibers are characteristic of muscle tissues, which are included in the work at loads that are in the range from 20 to 25% of the maximum possible force. They are characterized by excellent endurance. However, the red fibers do not work for sprint distances, heavy lifting, etc., since these types of loads involve a fairly rapid consumption and gain of energy. For this, white fibers are intended, which we will now talk about.

White fibers

They are also called fast, fast twitch type 2 fibers. Their diameter is larger compared to red ones. For energy production, they mainly use glycolysis (that is, their energy production system is anaerobic). Fast fibers contain less myoglobin. This is why they are white.

ATP breakdown

Fast fibers are characterized by high activity of the ATPase enzyme. This means that the breakdown of ATP occurs quickly, and a large amount of energy is obtained, which is needed for intensive work. Since white fibers are characterized by a high rate of energy expenditure, they also need a high rate of recovery of ATP molecules. And it can only be provided by the process of glycolysis, since, unlike oxidation, it occurs in the sarcoplasm of muscle fibers. Therefore, oxygen delivery to mitochondria is not required, as well as energy delivery from the latter to myofibrils.

Why white fibers tire quickly

Thanks to glycolysis, lactate (lactic acid) is formed, which accumulates rapidly. Because of this, the white fibers fatigue quickly enough, which ultimately stops the muscle from working. Red fibers are not formed during aerobic formation. That is why they can maintain moderate tension for a long time.

Features of white fibers

White fibers are characterized by a large diameter relative to red ones. In addition, they contain much more glycogen and myofibrils, but they have less mitochondria. A muscle fiber cell of this type also contains creatine phosphate (CP). It is required at the initial stage of high-intensity work.

Most of all, white fibers are adapted for making powerful, quick, but short-term efforts, since they have low endurance. Fast fibers, in comparison with slow ones, are able to contract 2 times faster, and also develop strength 10 times greater. It is thanks to them that a person develops maximum speed and strength. If the work requires 25-30% of the maximum effort or more, this means that it is the white fibers that take part in it. They are divided according to the method of obtaining energy into the following 2 types.

Fast glycolytic fibers of muscle tissue

The first type is fast glycolytic fibers. They use the glycolysis process to generate energy. In other words, they are able to use only an anaerobic energy production system that promotes the formation of lactic acid (lactate). Accordingly, these fibers do not produce energy with the participation of oxygen, that is, an aerobic way. Fast glycolytic fibers are characterized by maximum contraction speed and strength. They play a major role in the mass gain of bodybuilders and also provide sprint runners and swimmers with maximum speed.

Fast oxidative-glycolytic fibers

The second type is fast oxidative-glycolytic fibers. They are also called transitional or intermediate. These fibers are a kind of intermediate type between slow and fast muscle fibers. They are characterized by a powerful system of energy production (anaerobic), but they are also adapted to the implementation of a fairly intense aerobic load. In other words, these fibers can develop high forces and a high rate of contraction. In this case, the main source of energy is glycolysis. At the same time, if the rate of contraction becomes low, they are able to use oxidation quite efficiently. This type of fiber is used when the load is 20 to 40% of the maximum. However, when it is about 40%, the human body immediately completely switches to the use of fast glycolytic fibers.

The ratio of fast and slow fibers in the body

Studies have been carried out, in the process of which it was established that the ratio of fast and slow fibers in the human body is genetically determined. If we talk about the average person, he has about 40-50% slow and about 50-60% fast. However, each of us is different. In the body of a particular person, both white and red fibers can prevail.

Their proportional ratio in different muscles of the body is also not the same. This is due to the fact that muscles and their groups in the body perform different functions. It is because of this that the transverse muscle fibers are quite different in their composition. For example, triceps and biceps contain approximately 70% of white fibers. Slightly less of them in the thigh (about 50%). But in the gastrocnemius muscle these fibers are only 16%. That is, if more dynamic work is included in the functional task of a particular muscle, there will be more fast ones in it, not slow ones.

The relationship of potential in sports with muscle fiber types

We already know that the general ratio of red and white fibers in the human body is genetically inherent. Because of this, different people have different potential in sports activities. Some people are better at sports that require endurance, while others are better at strength. If slow fibers predominate, skiing, long-distance swimming, etc., are much more suitable for a person, that is, sports in which the aerobic energy production system is mainly involved. If there are more fast muscle fibers in the body, then you can achieve good results in bodybuilding, short-distance running, sprint swimming, weightlifting, powerlifting, and other types where explosive energy is of primary importance. And, as you already know, only white muscle fibers can provide it. Great athletes-sprinters are always dominated by them. Their number in the muscles of the legs reaches 85%. If there is an approximately equal ratio of different types of fibers, average distances in running and swimming are perfect for a person. However, the above does not mean at all that if fast fibers prevail, such a person will never be able to run a marathon distance. He will run it, but he will definitely not become a champion in this sport. Conversely, if the body has a lot more red fibers, the results in bodybuilding will be worse for such a person than for the average person, whose ratio of red to white fibers is approximately equal.

It's not a secret for anyone that there are different types of muscle fibers, but if you skipped the subject of human anatomy at school and did not know about it, then I advise you to read this post to the end. This information will be very useful to you, even if you are a beginner athlete and just went to the gym, keep this article for yourself, in the future you will have to face it.

So, let's begin! We will not go deep into anatomy and biochemistry, but will try to consider everything in an accessible and interesting language. There are two types of (main) muscle fibers, namely fast and slow muscle fibers. We are with you now and will consider each type separately.

Fast muscle fibers (white)

This type is also called "white muscle fibers". They perform the function of high-speed movements and are capable of rapid, so to speak, explosive muscle contractions. This is a big plus, but also a minus, because fast fibers tend to tire quickly. It is this type that predominates among bodybuilders and is quite well developed. Also, this type of fiber is capable of increased hypertrophy. Grypertrophy is the ability to increase the volume and mass of organs or cells under the influence of various factors. There is so-called true and false hypertrophy. False means an increase in the volume and mass of an organ due to an increase in the fatty layer (adipose tissue).

And at the heart of the "true hypertrophy" is, as you might have guessed, a natural increase in mass, due to an increase in the load on one or another organ, it is also called working hypertrophy. It is she who is developed in people who are involved in strength sports. We will not delve into the concept of hypertrophy, you understand the principle. Move on!

From the above, it follows that in those people who have more fast fibers, they are capable of a more intensive increase in muscle mass. Such people are unconditionally strong, and lift enormous weights, but many have very little endurance. Of course, if the athlete does not exercise and does not focus on training to increase endurance, in this case, strength endurance will be at the level. In bodybuilding, such people with a predominance of white fibers have been called genetic monsters. They are capable of colossal gains in muscle mass.

Fast fibers are also classified into two types: transient and fast. A brief description of:

Transitional (intermediate) muscle fibers: used for prolonged anaerobic exercise. This type is somewhere between fast and slow, and can use both aerobic and anaerobic for energy production. The source of energy for them is creatine phosphate, as well as glycogen.

Fast muscle fibers: the rate of contraction in this subspecies is very high, it is distinguished by a great ability to hypertrophy and a high rate of fatigue. Used in strength training. As well as transitional, fast fibers are fed with energy from creatine phosphate and glycogen. And it is this type of fiber that is of great value for the bodybuilder, therefore, almost all workouts are designed for this type of muscle fibers.

Training program for fast muscle fibers.

Slow muscle fibers (red)

If the considered white fibers have a high rate of contraction, then in the case of slow ones, this rate rather low, however, in comparison with their neighbors, they have the opportunity to work for a rather long period of time. Also, they are called red muscle fibers, because they have a more reddish tint, since they contain more myoglobin. Since we already mentioned this earlier in the article about, we will not go deeply.

Slow fibers are needed in our body to perform a number of functions:

1. Maintaining our core (posture), i.e. back muscles
2. Also for heat production
3. And finally, to perform a dynamic or aerobic load, namely: long distance running (long run), swimming, cycling, crossfit, etc.

These muscle fibers have little ability to grow or hypertrophy, but other research shows that the approximate ratio of fast and slow fibers is the same in our body. However, if you have a predominance of slow muscle fibers, the results in strength sports will be worse, and in athletics, races, the results will be pleasing. :)

findings

Genetic predisposition to one or another type of muscle fiber is not a sentence. You can always argue with nature. If you are not predisposed to large volumes, do not get upset and try anyway, only through hard work will you reach your goal! And remember, if you want good muscle work in your workout, you should definitely do

A person has oxidative ( slow), and glycolytic ( fast) muscle fibers. The former have a red color, which is due to the high content of oxygen molecules in them. The latter are white, since they use anaerobic glycolysis as the main energy resource, with the participation of creatine phosphate. How important is this information for the fitness enthusiast? It can help you overcome plateaus in strength sports and achieve more muscle hypertrophy if the goal is body aesthetics.

Fast muscle fibers and their role

Glycolytic muscle fibers are designed to do work with high power, but short duration. For example, when pushing a barbell, or running 50 meters, we train them mainly. They use "carbohydrate" fuel, that is, they feed on the glycolysis process. The predominance of white muscle fibers means that a person is naturally prone to strength training with low repetitions and significant weights. He can do more work per unit of time if “more” is a significant weight on the bar, and not the number of repetitions.

Fast muscle fibers are often not prone to hypertrophy (large volume), but rather stiff. People with their predominance may not be endowed with great muscle mass initially. But they are just one of those who press their weight in their first workout, and everyone around them is surprised at how this happens, since they do not see impressive muscle hypertrophy.

Slow muscle fibers and their role

Now imagine that we are doing the same barbell push, but for a large number of repetitions, as CrossFit athletes do. Fast muscle fibers in about 30 seconds depleted the resources of glycogen and creatine phosphate and got tired. And we need to keep moving. Then the so-called slow muscle fibers are recruited. They run on "aerobic" fuel and can perform many contractions. People with their predominance will have a predisposition for CrossFit, bodybuilding pump training and ... all sports that require endurance, but not explosive strength.

It is often said that slow muscle fibers are useless in terms of building a beautiful figure, but this is not the case. You can achieve their hypertrophy with the help of competent and regular training.

What fibers are more, and does it matter when training

The predisposition to certain sports depends on anthropometry (bone structure, limb length, angle ratio in basic exercises), body composition (predisposition to gaining fat mass), hormonal levels, and the predominance of certain muscle fibers. But a significant role is played by how the human central nervous system processes the load, and what exactly he wants to do.

If we are talking about amateur fitness, when the goal of training is beauty and health, and not medals and cups of serious competitions, knowledge of the prevailing type of muscle fibers can build a training program so as to achieve results faster.

For people with a predisposition to multi-repetition work, "bodybuilding" workouts have been created for 8-12 repetitions in basic, and 15-20 repetitions in isolating exercises. Such fitnessists tolerate cardio load well, which means they will be able to successfully fight excess body fat.

If there is a predisposition to strength training in a low-rep mode, mastering the base will be ideal, and, for a beginner, work in the range of 5-6 repetitions, and for continuing - and in a smaller number of repetitions too. Adding relatively high repetitions is still necessary to achieve a more balanced development, but the foundation can be built on training borrowed from the arsenal of powerlifting.

In either case, it makes no sense to dwell on any one style of training, it is better to use a yearly cycle in which the load will periodically change its volume and intensity.

Most people have about the same number of muscle fibers, so combined training, or cycling, is suitable for them. Try to build your training harmoniously, combine it different elements, and you will definitely achieve your goal, whatever it may be.

You need to know exactly which muscle fibers prevail in certain muscle groups, which can be determined using special tests. I'll tell you about them.

We are all different

Should you try to reach high training weights with low reps, or focus on medium weight and high reps? The most interesting thing is that no universal recipe.

Someone will progress from pure strength work with low reps. For some, on the contrary, strength training will not evoke a response to muscle growth and will not give progress, but an emphasis on increased number of repetitions with an average weight will have a huge effect.

Experienced athletes, over the years of training, intuitively find the most suitable scheme for themselves. Please note that in their YouTube videos, most of these comrades say: “ I do not have a clearly defined exercise plan for today's workout, I will do what I see fit and in such a mode that suits my body at the moment". These are bodybuilding stars, and simpler, addicted citizens who have spent years working with weights.

Sooner or later, many intuitively find their type of training if they are not too lazy to experiment, but why waste time when you can do everything much faster and without unnecessary experimentation?

First, let's deal with myths about universal training.

Equalization does not work

It actually works, but not very efficiently. By leveling I mean classical periodization of loads.

This is when you work for a certain period of time for strength with a small number of repetitions and large weights, then move on to medium-repetition training with moderate weights, then give preference to light weights, increasing the number of repetitions and reducing the rest time between sets.

Someone works on strength for a week, a week in an average mode, a week in an easy mode. Someone has cycles of 2-3 weeks, for a month. The pros usually have a "mass set" for several months with a fierce jam and huge working weights, and then "drying" for a couple of months. These are the hefty cycles between competitive seasons.

But with the pros, not everything is so simple and often they are very gifted genetically comrades who are forgivable for any mistakes in training. Especially considering the use of serious sports pharmacology. At the same time, the most successful professionals just come to training intuitively, taking into account their own muscle structure.

It is more difficult for ordinary mortals and mistakes in training lead to stagnation. Even periodization doesn't always help. And if it helps, then not for long, since within its framework, certain muscles work effectively only in one of the cycles.

Roughly speaking, the classic repetition-to-outcome ratio often does not work. The scheme is about this and she is half a century old:

• 1–5 repetitions - for strength;
• 8–12 repetitions - by weight;
• 12–20 repetitions - for relief and endurance.

A person can puff up in attempts to increase strength, but the result does not grow - he treads in one place and remains at the same level for months, or even years. Likewise with mass work. Relief and endurance are generally a separate conversation, and for the former, a reasonable calorie deficit is more important than the number of repetitions.

Why is this happening? It's all about the ratio of muscle fibers of the first and second types... I talked about these types in detail in. Who is too lazy to look, here is the information:

• First type... These are slow muscle fibers, they are also red or oxidative muscle fibers (OMF). They contain many mitochondria, have a slow rate of contraction, a low rate of fatigue, and a small capacity for growth (hypertrophy). They also have low strength. Used for aerobic activity (running, cycling). The source of energy is fats.
• Second type... Fast muscle fibers, they are also white or glycolytic muscle fibers (GMF). In turn, they are divided into two subtypes:
  • Subtype IIa (transitional or intermediate, PMV). They contain an average amount of mitochondria, can utilize aerobic and anaerobic metabolism equally, have a high rate of contraction, a moderate rate of fatigue, and little ability to grow. They have high strength. Used during prolonged anaerobic exercise. The source of energy is creatine phosphate, glycogen.
  • Subtype IIb (true fast muscle fibers). They contain a small amount of mitochondria, use only anaerobic metabolism, possess maximum strength and the rate of contractions. They have high fatigue, but at the same time a great ability to hypertrophy. Actually, these fibers are the most important for bodybuilders and strength athletes, as well as for sprinters. The energy source is creatine phosphate, glycogen.

To simplify, then the more fast muscle fibers a person has (Subtype IIb), the more it is prone to muscle hypertrophy and strength growth. That is, the emphasis should be placed on power trainingto realize the potential of a large number of such fibers.

The more he has slow muscle fibers, the less the potential for growth in strength and mass, but such a person is much more resilient. Again, hypertrophy in slow muscle fibers is also present, so there is already an emphasis on the number of repetitions, and it is in this mode that a person will progress both in strength and in mass.

If prevail intermediate muscle fibers (Subtype IIa), then training with medium weights and an average number of repetitions in the range of 8 to 12 will be most effective.

BUT! Every person has all types of muscle fibers, just a different ratio. So you shouldn't forget about other types of training in order to grow muscles as efficiently as possible, realizing your genetic potential.

Where and which muscle fibers prevail

Some muscle groups in our body are constantly under load, which has determined them, so to speak, a universal structure for all. As you can imagine, we are talking about slow muscle fibers, which are not very strong, but hardy. Although, how to say "not very strong." For example, the calf muscles are second in strength in our body after the muscles that compress the jaws (pressure up to 150 kg per cm²).

Whatever it was, but in the following muscle groups, almost all it is slow muscle fibers that predominate, which only grow when working for a large number of repetitions:

• Calf and soleus muscles.
• Trapeziums and extensors of the back.
• Forearms.
• Deltas.

Also, during everyday life, the muscles of the press, gluteal and hips (quadriceps and hamstrings) are very actively loaded by people. Intermediate muscle fibers often predominate there. But there are already more discrepancies and exceptions.

Concerning pectoral muscles, biceps, latissimus dorsi - this is the will of chance and genetics.

Fortunately, well-known in the world of foreign power sports Fredrik Hatfield (aka Dr. Squat) and Charles Poliquin They worked a lot on the scientific component of strength training, and on the basis of their work an algorithm was developed that determines the ratio of types of muscle fibers.

How to determine the individual ratio of muscle fibers

The algorithm can be applied to any muscle group by choosing an isolated exercise, but it still makes sense to focus on the largest. That is, on the back, legs and chest. Plus biceps - many have a problem with pumping it.

I personally conducted a pectoral test, finding out that fast muscle fibers predominate there (hurray, hurray - you can count on an impressive mass), but I'll tell you about personal results a little later, but for now let's go directly to the algorithm.

First step

Determine the maximum weight of weights with which you can perform one repetition. In the case of infants best exercise for this bench press.

note that test is not for complete beginners... Just arrived at the gym - exercise for several months under the supervision of experienced comrades, learn how to perform the exercises correctly and tone your muscles. Otherwise, you can get serious injury or the test results will be incorrect (due to the curve of the execution technique and the inability to use a large number of muscle fibers).

We work carefully so as not to get injured due to poorly warmed up muscles. I.e, first of all, warm up well with the bar, we rest for a couple of minutes. Then they threw in a little weight to easily squeeze it out 15 times and did 10 repetitions. Do a couple more sets in the same way, increasing the weight and doing 50% of the possible reps. Rest between sets - a couple of minutes.

Then, when the muscles are well warmed up, we throw in a serious burden that you can squeeze 3-4 times. We press it once, we rest 3 minutes minimum... In 3 minutes, the main energy reserves in the muscle are completely restored.

We rested, added 5 kg (or 5–10% of the total weight on the bar), squeezed out again, rested again for 3 minutes (but not more than 5), added another 5 kg, squeezed ... So we work until we reach that weight, which cannot be squeezed out. There was a bummer, no weight was taken - ok, you figured out your maximum weight that you can squeeze at one time. Remember it.

Second phase

Now directly we will determine the type of predominant muscle fibers in the tested muscle group.

In general, it is recommended to carry out the second stage after a notable rest and at another workout (after a good warm-up, of course). But if you are unbearable and want to know everything here and now, then after the last approach with the determination of the maximum weight rest 15–20 minutes... You should not sit - walk, strain your chest a little, spread your arms to the sides so that the muscles do not cool down completely.

After rested, subtract 20% from your maximum weight taken... Let's say you reaped 100 kg at a time, which means you leave 80 kg on the bar. Now the most important point - start doing the exercise for the maximum number of times you can do without breaking the technique and without outside help.

• If you have squeezed 80% of the maximum weight in 7-8 reps, which means that fast muscle fibers predominate in you. That is, this muscle group has great potential for growth in mass and strength. Thus, 75% of training should be in strength mode... If you break it down into a simple monthly cycle, then for three weeks you train pectorals hard (for 5-6 repetitions in basic exercises, up to 8 in more traumatic ones, like push-ups with weights), one week - with medium or light weights. Although there are a lot of splits and cycles, the main thing to understand is that 3/4 of the training should be strength in order to squeeze the maximum out of the potential of your muscles.
• If you managed to reap 9-10 timesthen equally of both types of fibers and we split the training 50 to 50 between strength and high-rep.
• "Pulled" 80% of the maximum weight on 11-13 times - you hardy, but not very strong, slow muscle fibers predominate... In this case, the emphasis in this muscle group is on multi-repetitive training, and only 25% of the total load in the cycle is allocated to strength.

To test other muscle groups, such exercises are suitable.:

• shoulders - military bench press or dumbbell bench press;
• biceps - standing up the EZ bar;
• triceps - French press;
• back lats - thrust of the upper block to the chest while sitting;
• legs - classic squats with a barbell on the shoulders.

Personal experience

At the moment, I did a pectoral test and found out the reason for stagnation in the bench press and in exercises for this muscle group in the last six months. The rest of the tests are still ahead, but only when my next big experiment is over, which I will talk about separately in the future.

Previously, I blamed that I do the classic bench press no more than once a month, and the rest of the time the emphasis was on working with dumbbells, blocks and in the Smith simulator at different angles of the bench. As it turned out, the problem is different.

In the midst of mine, which lasted about five months, at one time I squeezed lying 135 kg (yes, the power ones still fall; even though I hadn’t tried to reap for several years, but I felt it on the working weights). 80% of this weight, that is, about 108 kg, I squeezed 7 times (and another half of the time, but did not reach the end).

Thus, fast muscle fibers predominate in me and the emphasis should be on strength training, while for the most part I had work 12 times, and in isolated exercises up to 15 repetitions.

By the way, my coach (here it) squeezed 170 kg at a time, and 135 (80%) squeezed 12 times. That is, it is just the opposite - slow muscle fibers predominate. Actually, according to him, he always preferred to work on the chest with a large number of repetitions, which he came to intuitively.

So, a few days after the test, when the next chest training came up, I arranged for myself strength training... What can I say, except "Wow!". The whole workout took place at a completely different pace. I usually stumbled on the first two exercises, or even the first, doing 12 reps in four sets to failure. The rest of the training was not very cheerful.

Now, having worked in the range of 5-7 repetitions in the first exercise (bench press in the Smith machine with an incline of 45 °), I then very briskly lifted the dumbbells with much more serious weights than usual, and for the first time in several years I did push-ups from the bars with additional weight ... In general, it turned out to be much more comfortable for me to train the pectorals in the strength mode than in the medium or multi-reps.

Legs, back and biceps are on the agenda, but I'll be doing that in three months. In the meantime, another experiment is in priority.

Try to conduct such a test, and it is quite possible that it will turn out that the training is time to radically change, switching to strength training or, conversely, to multi-repetition for certain muscle groups. At the very least, this is another option for how to spur your muscles to intense growth.