Motor activity and its importance for the body. Effect on the body of insufficient physical activity Why lack of muscle activity

1.2. DEFICIENCY OF MUSCLE ACTIVITY

Restriction of muscle activity is one of the most important components of the symptoms of hypokinetic syndrome. A long-term change in the volume of muscle activity leads to a decrease in energy consumption, a decrease in bioenergetics and the intensity of structural metabolism in the muscles, a weakening of tonic impulses from the muscles, and a decrease in the load on the skeletal system [Kovalenko E. A., Gurovsky N. N., 1980]. Proprioception from the muscles during vigorous activity is a powerful source that maintains a constant sufficient level of trophism in almost all organs and systems, including the brain and higher centers of endocrine regulation [Mogendovich M.R., 1965]. Constant muscle activity is vital not only for the normal function of most systems and organs, i.e. effectors as such, but also for the central nervous system. It is in the motor analyzer that all cortical afferentations converge and converge, not only proprioceptive, but also exteroceptive and interoceptive. L. I. Kakurin (1968) was the first to point out the appearance of moderate muscle pain in the back region already with 20 days of hypokinesia. Together with M. A. Cherepakhin (1968), he also noted a decrease in muscle tone. V. S. Gurfinkel et al. (1968) observed a violation of motor automatisms (synergy) during 70-day hypokinesia, which manifests itself in a disorder of such integral acts as standing and walking, and the underlying innervation relationships. It has been established that staying in conditions of hypokinesia leads to the development of atrophic changes in the muscles [Kozlovskaya IB et al., 1982; Hristova L. G. et al., 1986]. The support unloading factor is of great importance in the pathogenesis of motor disorders in conditions of hypokinesia. The decrease in the influx of support stimuli, which plays a leading role in the control system of postural-tonic reactions, caused by this factor, causes a decrease in the tone of the “anti-gravitational muscles” and, therefore, triggers a chain of reactions characteristic of the atonic syndrome [Hristova L. G. et al., 1986] . According to the same authors, after a 3-day stay under immersion conditions, the properties of action potentials of muscle fibers changed significantly, which was expressed in a decrease in the rate of propagation of excitation. The leading role in the development of changes belongs to disturbances in trophic influences resulting from a decrease in afferent inflow under conditions of support unloading, atony, and an almost complete absence of motor activity.

In rats with limited motor activity, changes in metabolism were revealed [Ilyina-Kakueva E. I., Novikov V. E., 1985]. In the soleus muscle, the activity of flavin oxidative enzymes changed, which was expressed in a significant increase in the activity of glycerophosphate dehydrogenase and a significant decrease in the activity of succinate. The authors believe that the reason for the increase in the activity of glycerophosphate dehydrogenase is the need to utilize lipids released during the massive breakdown of the membrane structures of muscle fibers undergoing atrophic and dystrophic processes. A significant decrease in the activity of succinate dehydrogenase, which is one of the key enzymes of the tricarboxylic acid cycle, and a slight change or no change in the activity of other enzymes of this cycle indicate a selective disturbance in the muscle fibers of the process of converting succinic acid. With the restriction of motor activity in the muscles, the content of glycogen was found [Blinder L. V., Oganov V. S., Potapov A. N., 1970; Cherny A. V., 1975; Ilyina-Kakueva E. I., Portugalov V. V., 1981; Zipman R. L. et al., 1970].

According to V. S. Oganov (1985), under conditions of prolonged bed rest, the functional capabilities of muscles decrease, and movement disorders observed after relative inactivation of the muscular apparatus are to a certain extent due to adaptive functional atrophy of individual muscles or muscle groups.

Changes in the physiological properties of the skeletal muscles of humans and animals with limited motor activity are considered as a manifestation of the functional plasticity of skeletal muscles.

Under conditions of antiorthostatic hypokinesia lasting up to 182 days, a twofold decrease in the electromechanical efficiency of muscles was found [Oganov V.S., 1982; Rakhmanov A. S. et al., 1982]. Maximum plantar flexion strength throughout the study was below baseline. Hypotrophy and hypodynamia of some muscle fibers under these conditions lead to the activation of an additional number of motor units to perform equivalent work. This is accompanied by a disproportionate increase in muscle electrical production and, accordingly, indicates a decrease in the electromechanical efficiency of the muscle as a whole. In the later periods of the experiment, the specific bioelectrical activity of the muscles increases, which, in the absence of a significant synchronous decrease in strength, may reflect their increased fatigue. This is consistent with the data on the restructuring of human muscle metabolism during hypokinesia towards the activation of glycolysis processes against the background of aerobic respiration inhibition [Kovalenko E. A., Gurovsky N. N., 1980].

Hypokinesia in rats lasting from 22 to 30 days is not accompanied by a noticeable decrease in muscle mass, with the exception of the shoulder muscle. On the contrary, an increase in the mass of the soleus muscle in relation to body weight was found. After 22 days of hypokinesia, there was a tendency to increase the average fiber diameter, isometric contraction and performance of muscle fibers, more noticeable in the soleus muscle and the medial head of the triceps brachii muscle; a tendency to decrease in efficiency was noted in the shoulder muscle [Oganov V.S., 1984]. Under conditions that are usually defined as hypokinesia, there does not seem to be any actual inactivation of the postural muscles in rats. There is evidence of an increase in the motor activity of animals as a manifestation of a stress reaction during a month of their stay in cramped cages [Gaevskaya MS et al., 1970]. During this period, signs of activation of the pituitary-adrenal system were found in rats [Portugalov VV et al., 1968; Kazaryan V. A. et al., 1970], as well as other manifestations of the general stress reaction [Kirpchsk L. T., 1980]. With longer hypokinesia (90 and 120 days), there was a slowdown in the isometric contraction of soleus muscle preparations [Oganov V.S., Potapov A.N., 1973], while no changes in absolute muscle strength were found. The specific biomechanical effect of hypokinesia may be due to an increased load on the extensors of the foot in the form of prolonged stretching when animals are kept in cramped cages. During forceful unloading of the muscles (“hanging out” model), mass loss was noted in the soleus muscle and the medial head of the triceps brachii muscle, as well as a decrease in the average diameter of muscle fibers. In accordance with this, a decrease in the amplitude of their isometric contraction was noted [Oganov V. S. et al., 1980]. The leading biochemical factors that change the conditions for the functioning of various muscles under conditions of hypokinesia are their force unloading and a decrease in the tonic component of movements. With hypokinesia in dogs, created by muscle inactivation, functional atrophy of the gastrocnemius and plantar muscles developed, expressed in a decrease in strength, mechanical power and performance [Kozlova V.T. et al., 1977]. Functional insufficiency of the muscles active in the support period of the step, in turn, causes the disorganization of locomotion observed after experimental effects, manifested by instability of the gait, an increase in the rate of movements, lengthening of the support period and the phase of double support, an increase in the amplitude and speed of vertical movements in the distal joints of the hind limbs, disproportionate an increase in the energy of the bioelectrical activity of the muscles. According to V. S. Oganov (1984), the changes that develop in the skeletal muscles of humans and animals during hypokinesia are a special case of the manifestation of their functional plasticity.

Muscle weakness is a common problem with which patients turn to doctors of various specialties. In medicine, the term muscle weakness refers to a decrease in muscle strength, measured objectively. The extent of this damage may vary. Paralysis is the complete absence of voluntary movement in any muscle group. The weakening of such movements is called paresis.

Causes of muscle weakness

Muscle weakness can accompany completely different diseases. Usually such a complaint is voiced at the appointment with a neurologist or therapist. Often, patients mean fatigue, decreased sensitivity, difficulty in movement, and even a decrease in overall vitality. Adults are more concerned about muscle weakness in the legs. It is known that heart failure manifests itself in the appearance of shortness of breath and a decrease in the ability to perform physical work, even walking. Some patients misinterpret this condition as muscle weakness. Deforming osteoarthritis of large joints significantly reduces the range of motion in them, which also contributes to a decrease in the tolerated loads and can be perceived as weakness in the muscles. Even in adults, metabolic disorders, including type 2 diabetes, are widespread. This disease is accompanied by diabetic polyneuropathy, in which peripheral neurons are most often affected, and muscle weakness appears in the legs. All these causes of muscle weakness mainly appear after the age of forty. In a child, muscle weakness often indicates a pathology of the nervous system. Already in the first minutes of life, the pediatrician assesses the condition of the newborn, including muscle tone. A decrease in tone is associated with birth injuries and other causes. So, the causes of muscle weakness are varied. They can be diseases of the nervous tissue (central and peripheral nervous system), endocrine disorders (adrenal insufficiency, thyrotoxicosis, hyperparathyroidism), other conditions (dermatomyositis or polymyositis, muscular dystrophies, mitochondrial myopathies, hysteria, botulism, various poisonings, anemia).

Diagnosis of the disease

To determine the cause of muscle weakness, a complete examination of the patient is carried out. The doctor talks with the patient: finds out when the symptoms of muscle weakness first appeared, what affects the manifestations of the disease, in which muscle groups the lesion is localized. In addition, previous illnesses, heredity for neurological diseases and concomitant symptoms are important for diagnosis. Next, a general objective examination of the patient and a study of the muscles are carried out. At the stage of muscle assessment, the volume of muscle tissue, the symmetry of its location, and tissue turgor are determined. Mandatory is the assessment of tendon reflexes. The severity of the reflex is assessed on a scale that has six gradations (lack of reflexes, decreased reflexes, normal, increased, transient clonus, stable clonus). It should be noted that in a healthy person, superficial reflexes (for example, abdominal ones) may be absent, and the Babinski reflex is the norm in newborns. Muscle strength is evaluated on a special scale. The absence of muscle contractions corresponds to zero, and full muscle strength to five points. Points from one to four assess different degrees of decrease in muscle strength. With damage to the central nervous system, weakness manifests itself in the limb opposite to the lesion in the brain. So, if a stroke occurred in the left hemisphere, paresis and paralysis develop in the right limbs. In the arms, the extensor muscles suffer more than the flexor muscles. In the lower extremities, it is usually the other way around. With damage to the central part of the nervous system (brain and spinal cord), weakness is accompanied by an increase in muscle tone, revival of deep tendon reflexes, and the appearance of pathological reflexes (Hoffman, Babinsky). With damage to the peripheral nervous system, weakness is limited to damage to the zone of innervation of a particular nerve; muscle tone is always low; deep reflexes are weakened or absent. Sometimes there may be rapid twitches of muscle bundles (fasciations). To clarify the diagnosis, some functional tests can be carried out: the patient is asked to make this or that movement.

Treatment of muscle weakness

After establishing the diagnosis, the doctor chooses the treatment of muscle weakness according to modern recommendations. If the pathology of the nervous system has become the cause of muscle weakness, the therapy is carried out by a neuropathologist. Physical therapy, massage, physiotherapy, symptomatic therapy, thrombolytics, neuroprotectors, vitamins and other drugs can be used. In a child, muscle weakness is detected and treated by a pediatric neurologist and pediatrician.

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The value of physical activity for a person

Many centuries ago, a person had to actively move in order to get food, build a home, make clothes, etc. Therefore, they say that our body is created for movement. In a developing organism, the cell stores more energy than it uses. This is the so-called skeletal muscle energy rule. Therefore, one of the factors that cause and determine the growth and development of the body is the motor activity of the muscles.

In early childhood, physical exercises contribute to the development of speech, at school and university - the stability of mental performance and mental activity.

Movement is a condition for the development of a young organism, its health, character and attractiveness. Movement is closely related to the emotional state of the body. It relieves stress, affects hormonal phenomena. Muscular activity is constantly accompanied by emotional tension and "removes" its excess. This is due to the fact that the movement stimulates the production of hormones - endorphins and reduces excess adrenaline and hormones that contribute to stress.

Mastering the culture of the movement will help develop the ability to "rule oneself", that is, to maintain emotional balance in any situation, goodwill, respect for the emotional state of another person.

The modern life of a student - classes at school, preparing lessons, reading, TV - predisposes to a sedentary lifestyle. It turned out that about 18 hours a day (including sleep) the teenager is in complete or relative immobility. He has only 6 hours left for outdoor games, walks, sports. The lack of movements affects the general condition of the body: pressure often changes (it becomes either high or low), bones become fragile, a person gets tired quickly, mood changes dramatically. The lack of movement - physical inactivity, as well as overeating, smoking, causes the development of cardiovascular diseases.

A sedentary lifestyle, especially in youth, is not harmless. It leads to a change in the functions of all organ systems and diseases, in particular, the cardiovascular system. Active movement is a sign of a healthy lifestyle.

Low physical activity

Physical inactivity - reduced physical activity - is characteristic of modern urban civilization. Meanwhile, for a healthy person, systematic physical activity is necessary, starting from childhood and adolescence. Hypodynamia leads to detraining of regulatory mechanisms, a decrease in the functionality of the musculoskeletal system, often to a drop in working capacity and a weakening of the protective functions of the body.

Insufficient physical activity is often combined with obesity. With little physical activity, the adaptability of the cardiovascular system worsens even to light loads. In physically inactive people, the heart rate is on average 10-20% higher than in physically active people. An increase in the heart rate by 5-10 beats per minute leads to an additional number of contractions in just one day by 7-14 thousand. This additional work is done constantly at rest, its volume increases sharply during exercise. Studies have shown that people with high physical activity are 2 times less likely to get myocardial infarction and 2-3 times less likely to die from it compared to physically inactive people.

Why is movement and physical activity so necessary for the human body?

Regular physical activity increases the performance of the heart muscle, creates the opportunity for the cardiovascular system to work in the most favorable mode, which is especially important during physical and nervous overload. Regular physical activity contributes to a better blood supply to all organs and tissues, including the heart muscle itself. Constant physical activity contributes to the training of the mechanisms that regulate the coagulation and anticoagulation systems, which is a kind of prevention of blockage of blood vessels by blood clots - the leading cause of myocardial infarction; improves the regulation of blood pressure; prevents cardiac arrhythmias.

The computer has taken away a significant part of the physical activity of a person. Photo: Bruno Cordioli

During physical activity in skeletal muscles, which make up 30-40% of body weight, there is a sharp increase in energy consumption, which stimulates the activity of the cardiovascular system, trains the heart and blood vessels. Causing a significant energy expenditure, regular physical activity contributes to the normalization of metabolism and helps to neutralize the effects of excess nutrition. According to some authors, physical exercise and an active lifestyle can significantly (up to 50%) reduce the level of cardiovascular disease.

In modern society, the level of physical activity of people has decreased significantly, as production and living conditions have changed dramatically. Over millions of years, people have adapted to great physical exertion, the periodic absence or lack of food. Detraining and overnutrition are the scourge of modern humanity. Who among us has not seen how young people wait for an elevator for a long time, instead of walking up one or two floors. Many are ready to stand idle at public transport stops, but it never occurs to them to go through several stops on foot. The point here is not a lack of time, but over short distances, with the irregularity of transport, there is often no gain in time.

Students are not allowed to run during breaks. Many schools have introduced the so-called changeable shoes. It turns out that for the sake of cleanliness at school, children are deprived of the opportunity to run out to the school yard during the break, run around, play, and physically discharge themselves. Teachers, of course, made life a little easier for themselves, but are there schools for them?

Some parents consider an exemplary child to be one who sits at home from morning to evening. If he spends a lot of time in the yard (on the street), then he risks getting scolded for soiled clothes and a bruise received in the game.

A normal, healthy child, as a rule, is restless, active, a walk for him is not only a pleasure, but a physiological necessity. Unfortunately, parents often deprive their children of the opportunity to walk if they have learning problems. Naturally, such educational measures often lead to a result opposite to what was expected. Instructions, like: “First, do all the homework, and then go for a walk!”, speak of the parents’ lack of elementary ideas about the hygiene of study and rest. After all, before that, the child worked at school for 5-6 hours. This fact cannot but cause concern: with age, the physical activity of a schoolchild falls. Studies conducted among Australian schoolchildren showed that at the age of 13, 46.5% of boys and 24.6% of girls are actively involved in sports, and at 17 years, only 10.3 and 3.9%, respectively. Not too comforting figures were obtained during the examination of our schoolchildren. They also show a decrease in physical activity as they get older, with some girls also experiencing a decline in exercise capacity. We often rely too much on physical education lessons at school or vocational schools. Undoubtedly, the introduction of a physical education lesson or a physical culture break is a good thing, but without everyday physical activity, which is the true need of the body, it is unrealistic to expect significant changes in health status. Sometimes one hears such an opinion: if a person does not want to go in for sports, increase his physical activity, you should not interfere with him, otherwise he will commit violence against himself and this will not lead to anything good. It seems to us that such a judgment is unconvincing. Too many people justify their inertia, laziness with such “valid” reasons as overload at work, the desire to relax after a hard day, watch TV, read a book, etc. Considering this situation normal is the same as justifying smoking, drinking alcohol, overeating, because low physical activity is also a bad habit. We do not advocate that all without exception participate in sports competitions and go in for sections, although, undoubtedly, such a pastime could attract a much larger number of young people than is now observed. There is no sympathy for the desire of some parents to bring up record holders from their children at all costs. Big sport, associated with increased physical exertion, is not for everyone and is the lot of a few. We are talking about constant, moderate physical activity, taking into account the tastes and inclinations of each. It does not matter if a young man does not immediately find an attractive type of physical activity for himself, it is worse if he does not even try to find it.

Unfortunately, it is not uncommon for parents to seek to free their children even from physical education lessons at school, and doctors follow their lead and free the child from physical education lessons for a long time, even after a slight ailment, thereby creating obstacles to a quick recovery and improvement of health.

How to deal with hypokinesia?

Once you have made the decision to start a “new” life, it is advisable to get support from relatives and friends. Regardless of which way you decide to increase your physical activity, it is advisable to make it a rule not to use the elevator and public transport for short distances. Going to work or school, leave the house 10-15 minutes earlier and walk part of the distance.

Hypodynamia

One of the significant risk factors for the development of diseases of the cardiovascular system is physical inactivity. The level of physical activity today has decreased not only among urban residents, but also among rural residents, which is associated with a decrease in the share of physical labor both in industry and in agriculture. Even summer vacations and trips out of town at the end of the week, many people prefer to spend in the car, limiting walking, skiing and cycling to a minimum. Statistical studies have shown that among people who walk more than 1 hour a day, coronary heart disease occurs 5 times less than people who prefer transport to walking. There is also a clear relationship between the degree of hypodynamia and the possibility of developing hypertension. This is due to a number of reasons. First of all, physical activity significantly improves blood circulation, the mechanisms of its regulation and adaptation to the constantly changing demands of the body in accordance with different environmental conditions. Therefore, the reaction to the load in more physically trained individuals is carried out with a more economical expenditure of energy and with less activation of the sympathetic nervous system. It is also important that these people respond to emotional stress with a less significant increase in the activity of the sympathetic nervous system. Consequently, constant moderate physical activity adapts a person to emotional stress. Moderate and constant muscle tension has a calming effect on the central nervous system, which is also an important factor in the prevention of hypertension and coronary heart disease.

During exercise, the energy costs of the body increase and appetite decreases (in relation to energy costs), which prevents the development of obesity. An increase in physical activity with a parallel increase in energy consumption leads to an intensification of metabolism, promotes the utilization of fats and lowers the level of cholesterol in the blood, which is one of the most important factors in the prevention of diseases of the cardiovascular system.

Physical activity should be considered not only as the most important factor in preventing the development of heart and vascular diseases, but also as an essential part of the complex therapy of patients with many cardiovascular diseases.

Helpful Hints

Movement should be fun. When choosing the time for physical education and sports, be creative: do it every day before classes or immediately after returning home; team up with friends in sports, do exercises in any free time, force yourself to walk; when approaching the elevator, remember that there is a ladder. Don't let yourself be lazy.

Recently, exercise machines and gymnastic devices for individual use have become increasingly popular. These are exercise bikes, "health walls", treadmills, massagers and mini-training devices with game elements. They allow you to exercise all year round, regardless of weather conditions.

A sedentary lifestyle, especially in youth, is not harmless. It leads to a change in the functions of all organ systems and diseases, in particular, the cardiovascular system. Active movement is a sign of a healthy lifestyle.

Muscles do not grow: what to do?

Video: why muscle mass is not growing?

Muscle mass scientifically

A few months of grueling workouts do not give results? A reasonable question arises: why there is no increase in muscle mass. In most cases, this can be explained by overestimated expectations from a two- or three-month training. During this time, it is impossible to gain a few kilograms of muscle, remove fat and get the desired relief. No, of course, this is real if you use anabolic agents. Nearly all of the amazing before-and-after results on social media are the result of drug use. And what is most unpleasant is that only a few people admit this, thereby creating the already mentioned high expectations.

Even adherents of natural bodybuilding often use special preparations, but they carefully hide this fact. This is important, first of all, to promote your own training programs, methods and resources. If you doubt this, you can ask what the progenitors of bodybuilding looked like. For example, Charles Atlas and Georg Gakkeshmidt - they have exactly natural muscles that have been developed over the years, because no one knew about anabolic steroids during the period when they lived. Their body is the result of systematic strength training.

In order not to flatter yourself with illusions, it is worth understanding: it is impossible to quickly achieve results with natural natural training. This will take years. But you should also understand that if there is no result with proper nutrition, adequate training and the use of sports nutrition, there are good reasons for that.

Reasons for the lack of muscle growth

1. Heredity. It is your genes that determine the speed of metabolic processes, muscle growth, and even weight. Developing the right principles for building training will not help you gain growth if genetics are laid down that do not allow it. At this stage in the development of science, it has not yet been possible to find ways to change the human genotype, but bad genes are not yet an excuse for the lack of muscle growth. By creating optimal conditions for your own body, thereby interfering with metabolic processes, you can try to achieve your goals. But still, it is first worth evaluating your own potential.
2. Lack of purpose. Even at the very beginning of the training, you need to determine for yourself what weight you want to achieve, the volume of arms, legs, even the percentage of fat. The most important thing is that you feel comfortable within these limits.
3. Motivation. If it is absent or too weak, then obtaining a result is almost unattainable. About 50% of athletes quit after a couple of months after the start, another 30% say goodbye to their aspirations for an ideal body after six months. Another 10% in a year. By simple mathematical calculations, it can be understood that no more than 10% are ready to study for more than a year.
4. Gaps in knowledge. Many novice athletes do not have a theoretical background, and this affects the fact that they do not understand how malnutrition, the anabolic process and metabolism work. Of course, the easiest way is to turn to specialists, and the trainer will create the ideal training scheme, the nutritionist will select the right nutrition. If this is not possible, then before you take up dumbbells, you will have to study a lot of smart books. But this is not enough: you need to be able to use the information received for the benefit of your own muscles. Do not trust those "experts" who are ready to help you achieve results at the moment.
5. Lack of discipline. This is often the result of weak motivation. If a person does not know how to maintain a daily regimen and systematically perform exercises, then achieving a result is impossible. Planning is everything. Moreover, it is important to draw up a nutrition plan both on the days of training and in the rest of the period. Full and regular rest: if the goal is to build muscle, then you can forget about nightly entertainment, as well as bad habits. The result should be the focus. In order to do just that, you can use a training diary, nutrition, it’s good if there is a calorie counter. It is important to weigh regularly. Fix all the food that you eat, adjust the training in time.
6. Diseases. Sometimes the reason that the muscles do not grow can be a disease. For example, those that are ways to reduce the secretion of anabolic hormones such as testosterone, growth hormone, insulin. And also with increased formation of catabolic hormones, in particular cortisol. If all requirements are met, but there is no result, it is better to analyze the main anabolic hormones.
7. Overtraining. Yes, it is a significant number of workouts that can lead to a lack of muscle growth. If after a couple of months of training you do not see the result, you do not need to increase the number of workouts and load at times - in this case, the muscles will not have time to recover, which means that their growth will not be observed.