At what age muscle performance decreases. Muscular system development. Medical supervision of the elderly
The range of factors that have a negative impact on the neuromuscular apparatus of a person and his muscular performance is limited. The natural and strongest factor that has both a negative and a positive effect on skeletal muscles and motor functions of a person during all periods of life is the magnitude of the load on the musculoskeletal system. The most significant "blow" to the muscular system (at any age) causes a decrease in physical activity on it. At all stages of human ontogenesis, a decrease in motor activity causes a decrease in energy consumption, leading to inhibition of oxidative phosphorylation processes in muscle cells. At the same time, the rate of ATP resynthesis in muscles decreases and their physical performance decreases. In myocytes, the number of mitochondria, their size and content in their cristae decrease. The activity of phosphorylase A and B, NADH 2 -dehydrogenase, succinate dehydrogenase, enzymatic activity of ATP-ase of myofibrils decreases. The rate of breakdown and synthesis of energy-rich phosphorus compounds is slowed down and, therefore, muscle performance is reduced. To the greatest extent, this begins to manifest itself in adulthood (after 35-40 years).
The lack of an optimal level of physical activity in a person (daily energy consumption is less than 2800-3000 kcal) reduces the tone of skeletal muscles, their excitability and contractile properties, impairs the ability to perform highly coordinated movements, reduces muscle performance both during dynamic and static work, practically of any intensity ... The main reason for the decrease in the performance of muscles, especially those that are not active during the day, is a decrease in the content of contractile proteins in muscle cells due to a slowdown in the intensity of their synthesis processes. In conditions of weakening of physical activity and, consequently, a decrease in the intensity of disintegration of macroergs, the periodic stimulation of the genetic apparatus of the cell, which determines the synthesis of contractile proteins, weakens. Due to a decrease in the activity of phosphorylation processes in myocytes, protein synthesis slows down according to the DNA-RNA-protein scheme. With a decrease in physical activity, the production of hormones that stimulate the development of muscle tissue (androgens, insulin) slows down. This mechanism also leads to a slowdown in the rate of synthesis of Contracting proteins in skeletal muscle cells.
However, not only reduced physical activity, but also increased is also one of the factors that reduce the functionality of the locomotor system and contribute to the development of pathology of the neuromuscular system. Here (due to the specifics of the tasks of the textbook) there is no need to touch upon the influence of high physical stresses (for example, in weightlifters) on the development of pathology of the musculoskeletal system. This is the subject of sports medicine. At the same time, it should be emphasized that the work of millions of people is associated with the need to perform a large number (per working day) of physical movements with a small amount (from 100-500 g to 10-15 kg and more). So, for example, assemblers of electric motors, controllers-sorters, operators-assemblers of automobile plants, shoe collectors, operators of computer keyboard machines, telegraph operators make from 40 to 130 thousand finger movements per working day. At the same time, the total local work of small muscle groups often exceeds 100-120 thousand kgm per work shift. The degree of muscle fatigue that develops during such work, the subsequent overstrain of the neuromuscular apparatus and the professional pathology of the neuromuscular apparatus are determined by the number of movements per shift and the magnitude of the effort developed by the muscles. If the value of the total load exceeds a certain threshold level (for example, 60-80 thousand finger movements per shift), then the result is a decrease in muscle performance and the development of occupational diseases of the neuromuscular system is possible.
At all stages of human ontogenesis, the optimal activity of his musculoskeletal system or disorders of muscle functions depend on the intake of the necessary chemical substrates in the body: proteins, carbohydrates, fats, vitamins and minerals, i.e. from the structure of food.
Squirrels make up about 15% of body weight, predominantly found in skeletal muscles. Until the human body is completely devoid of its main energy substrates (carbohydrates and fats), the share of proteins in the energy supply of life does not exceed 1-5%. The main purpose of protein consumption is to use them in the growth and maintenance of muscle and bone mass, building cellular structures, and enzyme synthesis. In a person who does not perform significant physical activity, daily protein losses are about 25-30 g. With hard physical work, this value increases by 7-10 g. The required daily protein intake is greatest during periods of growth of the body and during heavy physical exertion. The minimum amount of protein consumed per day per 1 kg. body weight for children 4-7 years old is 3.5-4 g; 8-12 years old - 3 g and adolescents 2-2.5 g. After the completion of the growth of the body, it is necessary to consume about 1 g of protein per 1 kg of body weight. For persons performing heavy physical work, this value should be 20-30 % more. It must be remembered that even in the most protein-rich foods (meat, eggs), the protein content does not exceed 20-26 %. Consequently, in order to maintain a full-fledged protein balance, the value of protein products consumed by a person in comparison with the above norms of protein consumption must be increased by 4-5 times.
The main sources of energy for muscular work of a person are carbohydrates and fats. When I g of carbohydrates are "burned", 4.1 kcal of energy is released, air fats - 9.3 kcal. The percentage of the use of carbohydrates and fats during muscular activity of a person depends on the power of work. The higher it is, the more carbohydrates are spent, and the less - the more fats are oxidized. There are no special problems with the fat content in relation to the tasks of providing energy to the work of the musculoskeletal system at all stages of ontogenesis, since the existing fat depot in a person is able to provide the real needs of his body for energy during work of medium and moderate power for many hours. The situation is somewhat more complicated with carbohydrates.
The fact is that the performance of skeletal muscles is directly dependent on the content of carbohydrates (glycogen) in their fibers. Normally, 1 kg of muscle contains about 15-17 g of glycogen. At any age, the more glycogen muscle fibers contain, the more work they are able to do. The content of carbohydrates in the muscle depends on the intensity of the previous work (their expenditure), the intake of carbohydrates from food, the duration of the recovery period after exercise. To maintain a high working capacity of a person at all age periods, the general laws are: I) with any amount of carbohydrates in the daily diet in the absence of exercise, the glycogen content in the muscles changes insignificantly; 2) the concentration of glycogen in muscle fibers decreases almost completely with intensive work for 40-100 minutes; 3) complete restoration of muscle glycogen content requires 3-4 days; 4) the possibility of increasing the content of glycogen in muscles, and, consequently, their performance by 50-200%. To do this, it is necessary to perform muscle work of submaximal power (70-80% of the VO2 max) for 30-60 minutes (with such a load, glycogen will be mainly consumed) and then use a carbohydrate diet for 2-3 days (the carbohydrate content in food is up to 70-80% ).
ATP plays a leading role in ensuring muscle activity. At the same time, ATP resynthesis and, therefore, muscle performance largely depend on the content in the body vitamins. With a lack of B-complex vitamins, a person's aerobic endurance decreases. This is due to the fact that among the many different functions that are influenced by vitamins of this group, their role is especially great as cofactors in various enzyme systems associated with the oxidation of food and the formation of energy. So, in particular, vitamin W (thiamine) is necessary for the transformation of pyruvic acid into acetyl-CoA. Vitamin Bp (riboflavin) is converted to FAD, which acts as a hydrogen acceptor during oxidation. Vitamin Bo (niacin) is a component of NADP - a co-enzyme of glycolysis. Vitamin Btr plays an important role in amino acid metabolism (changes in muscle mass during exercise) and is required for the formation of red blood cells, which transport oxygen to muscle cells for oxidation processes. The functions of the B-complex vitamins are so interrelated that a deficiency of one of them can disrupt the utilization of others. Lack of one or more B vitamins reduces muscle performance. Additional use of this group of vitamins increases performance only in cases where the subjects had a deficiency of these vitamins.
Insufficient intake of vitamin C (ascorbic acid) with food also reduces the muscle performance of a person. This vitamin is essential for the formation of collagen, a protein found in connective tissue. Therefore, it is important for the maintenance of normal function (especially under heavy loads) of the osteo-ligamentous apparatus and blood vessels. Vitamin C is involved in the exchange of amino acids, the synthesis of certain hormones (catecholamines, anti-inflammatory corticoids), and in ensuring the absorption of iron from the intestine. An additional intake of vitamin C increases muscle performance only in cases where there is a deficiency in the body. Vitamin E (alpha-tocopherol) helps to increase the concentration of creatine in the muscles and develop more strength. It also has antioxidant properties. Information about the effect of other vitamins on muscle performance in untrained and in athletes is very contradictory. However, there is no doubt that without taking a daily intake of a full complex of vitamins, muscle performance can be reduced.
The importance of minerals in maintaining high muscle performance is beyond doubt. However, their additional need was noted only for persons performing long and large physical activity in a hot and humid climate.
Reception has a negative effect on motor functions alcohol. The data on this "risk" factor in relation to the activity of the musculoskeletal system are rather ambiguous. They are even less definite in relation to the effect of alcohol on the muscular system in ontogenesis. However, some of the proven statements about the effects of alcohol on the neuromuscular system are as follows.
I. Drinking alcohol leads to an increase in the processes of inhibition in the motor area of the cerebral cortex, worsens the differentiation of inhibitory processes during motor reactions, reduces the speed of switching the processes of inhibition and excitation, reduces the strength of the processes of concentration of excitement and the rate of increase in the frequency of impulses in motor motor neurons. 2. When alcohol is consumed in a person, the strength and speed of contraction of skeletal muscles decrease, which leads to a decrease in their speed-strength qualities. The manifestations of human motor coordination are deteriorating. 4. All kinds of reactions to external stimuli (light, sound, etc.) are slowed down. 5. The autonomic reactions to the same muscle work as before the intake of alcohol increase, that is, the physiological "cost" of the work increases. 6. The concentration of glucose in the blood decreases, thereby causing a deterioration in the functions of the muscular system. 7. The content of glycogen in the muscles decreases (even after a single intake of alcohol), which leads to a decrease in muscle performance. 8. Prolonged intake of alcohol leads to a decrease in the contractile function of human skeletal muscles.
Extremely limited information about the impact tobacco smoking on the functions of the musculoskeletal system. It is only known for certain that nicotine, getting into the blood, impairs the processes of regulation of the force of contraction of skeletal muscles, impairs coordination of movements, reduces muscle performance. Smokers generally have lower BMD values than non-smokers. This is due to the more intense addition of carbon monoxide to hemoglobin in erythrocytes, which reduces oxygen transport to working muscles. Nicotine, reducing the content of vitamins in the human body, helps to reduce its muscle performance. With prolonged smoking, the elasticity of the connective tissue decreases, and the elasticity of the muscles decreases. This leads to the occurrence of painful reactions during intense contractions of the human muscles.
Thus, along with many negative effects of tobacco smoking on the systems of the human body and their functions, nicotine also causes a decrease in muscle performance and the level of physical health of smokers.
One of the most widely used by people ergogenic means, that is, means of increasing efficiency, is caffeine... Acting on the central nervous system, caffeine increases its excitability; improves concentration of attention; cheers up; shortens the speed of sensorimotor reactions; reduces fatigue and delays the time of its manifestation; stimulates the release of catecholamines; enhances the mobilization of free fatty acids from the depot; increases the rate of utilization of muscle triglycerides. Through all of these reactions, caffeine produces a marked increase in aerobic performance (cycling, long distance running, swimming, etc.). Caffeine appears to also improve muscle performance in sprinters and strength athletes. This may be due to its ability to enhance calcium metabolism in the sarcospasmic reticulum and the work of the sodium-potassium pump in muscle cells.
Nevertheless, despite the indicated effect of caffeine on a person's performance, it can also cause negative consequences. insomnia, anxiety, skeletal muscle tremors. Acting as a diuretic, caffeine increases dehydration by disrupting thermoregulation processes, and reduces muscle performance, especially in high temperature and humidity environments.
Some athletes use drugs to speed up the recovery process after heavy physical exertion. Sometimes even cocaine is used. The latter stimulates the activity of the central nervous system, is considered a sympathomimetic drug, and blocks the reuse of norepinephrine and dopamine (neurotransmitters) by neurons after their formation. By blocking their reuse, cocaine enhances the effects of these neurotransmitters throughout the body. Some athletes believe that cocaine improves performance. However, this omission is misleading. It is associated with the emerging feeling of euphoria, which increases motivation and self-confidence. Along with this, cocaine "masks" fatigue and pain and may contribute to the development of overstrain in the neuromuscular system. Overall, cocaine has not been shown to have the ability to increase muscle performance,
To increase muscle performance, people involved in physical exercise and sports are often used hormonal drugs. From the beginning of the 50s, the era of the use of anabolic steroids began, and from the second half of the 80s, the use of synthetic growth hormone. Due to the greatest prevalence and the danger of use for the body, we will dwell only on androgens - anabolic steroids, almost identical to male sex hormones.
The use of anabolic hormones leads to a significant increase in: total body weight; the content of potassium and nitrogen in the urine, indicating an increase in lean body mass; the size of whole muscles and the cross-sectional area of their constituent myocytes due to an increase in the number of myofibrils contained in them (that is, the number of contractile proteins); strength and performance of skeletal muscles.
Therefore, the main effect of using steroid hormones is to increase the volume of muscle mass (myofibrillar hypertrophy) and force of contraction. At the same time, these hormones are practically do not affect on the aerobic endurance of a person, the speed qualities of his muscles, the speed of the processes of restoration of working capacity after intense physical exertion.
However, the use of steroid hormones (this sometimes happens already from school age) is not only a matter of ethics, but also a problem of maintaining the health of a huge number of people. Due to the high degree of health risk, anabolic hormones and synthetic growth hormone are considered illegal drugs. The main negative health effects of those taking steroid hormones are as follows. The use of synthetic anabolic hormones suppresses the secretion of its own gonadotropic hormones, which control the development and function of the sex glands (testicles and ovaries). In men, decreased secretion of gonadotropin can lead to testicular atrophy, decreased testosterone production and decreased sperm count. Gonadotropic hormones in women are necessary for the implementation of ovulation and the secretion of estrogens, therefore, a low blood level of these hormones as a result of the use of anabolic steroids leads to menstrual irregularities, as well as masculinization - a decrease in breast volume, coarsening of the voice, and the appearance of facial hair.
A side effect of the use of anabolic steroids can be an enlarged prostate gland in men. There are also known cases of liver dysfunction due to the development of chemical hepatitis, which can turn into liver cancer.
In persons who have been using anabolic steroids for a long time, a decrease in the contractile function of the myocardium is possible. They have a significant decrease in the concentration of high-density alpha-lipoproteins in the blood, which have antiatherogenic properties, that is, they prevent the development of atherosclerosis. Therefore, the use of steroid hormones is associated with a high risk of coronary heart disease.
The use of steroids leads to changes in a person's personality traits. The most pronounced of which is increased aggressiveness.
Changes in working capacity in different periods of work are characterized by ergographic and electromyographic indicators presented in table. 6. The first Period, defined as the period of training and assimilation of the rhythm, is characterized by the fact that by the end of it there is a slight increase in the amplitude of the ergogram, a decrease in the variability of this value and an increase in work productivity. As a result of these processes in the second period, there is an increase in the amplitude of motion from 92 to 97 mm, a decrease in variability from 6.5 to 5.7%; the consumption of bioelectric energy, expressed in conventional units (in millivolts per 1 cm of lifting the load) per unit of work, decreases from 4.2 to 4 mV.
All these changes indicate that the second period is the period of the highest efficiency. Table data. 6 explain the physiological mechanism of increasing performance during this period. This is a decrease in the time interval during which the nervous excitement has time to develop and come to an end, providing the muscle contraction necessary for a single flexion of the finger lifting the load. A decrease in the interval of nervous excitement can be judged by a decrease in the duration of volleys, or packs, bioelectric activity of the flexor and extensor muscles of the fingers. A decrease in the interval of excitation, or the assimilation of a high rhythm of activity of the nerve centers, is obtained due to the summation of traces of excitement that remain after each next movement.
Table 6. Changes in various indicators of working capacity by periods of work in boys aged 16-18 
After the period of the highest working capacity, a period of decreasing working capacity begins, at this time processes occur in the body that partially compensate for the incipient fatigue (the third period of the dynamics of working capacity). In this case, the ergogram shows a decrease in the amplitudes, alternating with their increase; the total bioelectric activity of muscles and the amplitude of muscle biocurrents slightly increase. In the fourth period of work, despite the effect of physiological compensatory measures, fatigue continues to deepen, which is expressed in a further decrease in the amplitude of the ergogram, in an increase in the variability of amplitudes, in a decrease in the productivity of bioelectric processes and in deconcentration of muscle strength and nervous processes.
In children of different ages, indicators of the dynamics of working capacity differ in both biomechanical and bioelectric processes. In children of primary school age, the peculiarities of work are observed, due to such quantitative indicators as the size and mass of muscles, as well as insufficiently developed mechanisms of mastering the rhythm and compensating for fatigue. Age characteristics of the dynamics of working capacity are presented in table. 7.
Table 7. Performance indicators in children of different ages (average values) 
As can be seen from these data, various indicators of working capacity change regularly with age. Thus, the amount of work performed per minute increases unevenly with age. Age-related increases in the amount of work performed depend on physical development. This position is confirmed by the results of statistical testing: it turned out that the correlation coefficient between the values of the hand force and the amount of work performed in one minute is 0.71. In young children, work took place with a relatively large variability in the duration of motor cycles, with some lag in the performance of work from the signals of the metronome setting the pace. For older children, a clear rhythm and less variability in the duration of motor cycles are characteristic. With an increase in the age of the subjects, the efficiency of work increases, the consumption of total bioelectric energy per unit of work (100 kgf · m) decreases. Between the increase in the work performed per minute and the amount of consumption of bioelectrical activity, an inverse close correlation was noted, the correlation coefficient was 0.77.
Aging is inherent in any living system, it is an inalienable property, an attribute of life and therefore is a normal, natural process.
Many researchers believe that the most common result of aging is a decrease in the body's adaptive capabilities.
Aging is a destructive process that develops due to the increasing damage to the body with age by external and internal factors. It leads to a lack of physiological functions, cell death, limitation of the adaptive capacity of the organism, a decrease in its reliability, the development of age-related pathology, and an increase in the likelihood of death.
Specific manifestations of aging, its rate and direction are determined by genetically predetermined features of the biological organization of the organism. The passport and biological age of a person does not always coincide. Biological age is a measure of changes in biological capabilities over time, the viability of an organism, a measure of the future life.
With various physical activities, emotional changes, there is a violation of homeostasis, a change in the internal environment of the body, a change in blood pressure, blood sugar, etc. in the course of violations of the internal environment of the body, they mobilize, improve the adaptive and regulatory mechanisms that contribute to the preservation of homeostasis.
Constant disturbances in the internal environment of the body contribute to the preservation of its "homeostasis" during a long life.
Movement is the most important attribute of life; there is no more physiological method of stimulating various systems of the human body than muscle activity.
In the process of muscular activity, tension of all body systems, oxygen starvation occurs. It constantly trains, the level of activity of the body. The influence of muscle activity is so great that the activity of the genetic apparatus, protein biosynthesis, changes. Strenuous activity leads to an increase in the mass of the volume of individual muscle fibers and the entire muscle as a whole.
Under the influence of systematic physical exercises in elderly people, the general condition improves, motor functions are restored, vascular tone decreases, blood supply to the heart and brain improves, working capacity increases, heart contractility increases, energy expenditures become more economical, etc. exercise is a means of maintaining health and prolonging life.
Systematic training helps to maintain the normal functioning of the main body systems - nervous, cardiovascular, respiratory muscle and others. However, with excessive physical exertion, overload phenomena often occur - coronary insufficiency worsens, blood pressure becomes unstable, and arrhythmias often occur. In this regard, it is very important to choose the right means of physical education, individually dose the load, and control its effect on the body.
It is no coincidence that the main focus of "basic" health and fitness clubs today is conditioning training based on bodybuilding.
Is it too late to get bodybuilding? With age, the muscle structure begins to atrophy at an ever-increasing rate. Bodybuilding is the best way to counteract this process.
However, in bodybuilding, starting late is not as crucial as it is in other sports.
Recent research (Bill Dobbins 2000) has shown that muscles do not necessarily have to atrophy with age to the extent commonly believed. In fact, older people can even significantly increase muscle volume with proper training.
The results can be very impressive. A noticeable surge of strength. Much more toned and muscular body. Energy, mobility, improved quality of life. Independence and self-confidence. What we consider to be inevitable aspects of aging are really just signs of a sedentary attitude and disregard for our own body.
From the point of view of physiological processes in adulthood, functional, reversible changes in the indicators of physical performance and fitness occur, then in old age a decrease in functional and physical capabilities is associated with organic, irreversible changes in the body. These disorders occur in the nervous, endocrine, cardiovascular, respiratory systems, and the musculoskeletal system.
In the musculoskeletal system, significant disorders are noted - the articular surfaces narrow, formations grow along the edges of the epiphyses of the bones, the bone tissue looses, its density decreases, the calcium content in the bones decreases, the content of synovial fluid in the joints decreases. Bones become fragile, brittle, very often the elderly have osteoporosis
Deformity of the spine appears, posture disorders increase the likelihood of diseases associated with joints - arthritis, arthrosis, etc. Decreases the amortization capacity of the joints, their mobility
Changes occur in muscles and ligaments, which lose their elasticity, signs of muscle atrophy appear - the number of motor neurons, fibers responsible for spastic contraction decreases, the concentration of myosin and actin decreases; the network of capillaries is reduced (deterioration of the blood supply to the muscles); the volume of connective tissue in the muscles increases. In elderly people, the speed of movement decreases, the potential muscular endurance and flexibility decrease. There is a weakening of the muscles in the pelvic region.
With age, changes are observed in the nervous system - the balance of inhibitory and excitatory processes is disturbed, as well as their strength, which is expressed in the difficult formation of new motor skills.
The cardiovascular system. The contractile function of the myocardium weakens, the efficiency of blood vessels decreases, and the supply of blood to the heart and other organs deteriorates. Deterioration of gas exchange, elasticity of the lungs and chest. The efficiency of the circulatory system becomes lower, the capillary network decreases and the volume of oxygen delivered to the cells decreases, the volume of blood passing through the heart decreases. Signs of increasing hypertension appear, the maximum heart rate decreases, and the sensitivity to fatigue and waste substances, such as lactic acid, increases. The likelihood of diseases of the cardiovascular and respiratory systems increases
In the respiratory system, there is a deterioration in the elasticity of the lung tissue, a weakening of the respiratory muscles, a limitation of the mobility of the chest, a decrease in pulmonary ventilation.
Nervous system. Short-term memory deteriorates, balance worsens, and the coordinating function of the central nervous system decreases. In this regard, in older people, there is a rapid forgetting of the sequence of movements, difficulties with maintaining balance, adopting a stable position, poor coordination of movements, and a decrease in the speed of performing movements. In the process of aging, the metabolism changes, it becomes less intense. This is due to the slowing down of oxidative processes.
The secretory and motor functions of the intestines are weakened, digestion is disturbed. The body's resistance decreases. Adaptation to loads worsens, activation and recovery slows down.
All this leads to a decrease in working capacity and physical fitness (a drop in the speed and accuracy of movements, impaired coordination, a decrease in the amplitude of movements, etc.).
The main causes of deterioration in physical performance in old age are:
1. Decreased physical performance is associated with:
- limitation of physical activity;
- limiting the possibility of intensifying the functions of individual body systems;
- dysregulation of the functions of the cardiovascular and respiratory systems;
- metabolic disorders;
- decreased aerobic and anaerobic performance;
- slowing down the recovery processes;
- decrease in the efficiency of work.
2. The decrease in strength is due to a decrease in active mass, a drop in the content of water, calcium and potassium in muscle tissue, leading to a loss of muscle elasticity.
3. Decreased endurance is associated with disruption of the oxygen transport systems.
4. A drop in speed is caused by a decrease in muscle strength, impaired coordination in the central nervous system, and a decrease in the function of energy-supplying systems.
5. Coordination, dexterity decreases due to deterioration in the mobility of nervous processes.
6. The deterioration in flexibility is associated with a change in the musculoskeletal system.
Thus, in old age, a decrease in functional and physical capabilities is associated with organic, irreversible changes in the body. These disorders occur in the nervous, endocrine, cardiovascular, respiratory systems, and the musculoskeletal system.
The level of strength required to carry out daily activities does not change throughout life. At the same time, the level of maximum strength, which exceeds the level of strength required to carry out daily activities, gradually decreases with age. Medical research data have shown that physical performance in each decade of life is 10-15% less than in the previous one.
It should be noted that the ability to get up from a sitting position deteriorates at the age of 50, and at 80, some people are unable to do so. Many medical professionals are of a less optimistic view of older people, namely that older people can and must do work that requires little muscle effort.
Sports physiologists believe that strength training allows older adults to perform better at age 60 than most physically inactive men half their age.
Strength capacity decreases with age as a result of decreased physical activity and muscle mass. The latter is mainly due to decreased protein synthesis due to the aging process and a reduction in the number of rapidly contracting motor units.
At the age of 50 and more, muscle tone decreases in men and women. The muscles of the back and abdomen are the first to weaken, which leads to deformation of the spine: the shoulders drop, the back becomes round, the abdominal muscles hang down. These negative manifestations, together with flat feet, reduce a person's height. The literature on this issue by scientific research proves that exercises with weights have a positive effect on changes in the morphological, biochemical and physiological systems of elderly people.
According to the study, it was determined that even in 60-70 year old people who are engaged in strength exercises, muscle hypertrophy and a decrease in the thickness of the fat layer are observed. For 2 years of strength training, such people showed an increase in absolute strength (by 50-100%), strength endurance (by 200-300%), VC, decreased heart rate and blood pressure.
As body fat decreases and muscle mass increases, other important changes will occur in terms of appearance, well-being, and more.
The aging process can contribute to a decrease in the level of strength ability, however, a decrease in the level of strength ability can also contribute to the aging process.
Thus, whether an organism ages or not depends on its ability to function fully and independently. Much of the evidence of the aging process is a consequence of the limited use of human capabilities.
Muscle strength tends to peak at age 30, and then, if no effort is made, muscle strength levels gradually decline. By the age of 85, the decline reaches about 45%. The decline in muscle strength with age is normal (even trained athletes have a slight decline in muscle strength between the ages of 60 and 65), but the decline in most older and physically healthy people is abnormally high because they tend to limit their motor levels. activity.
Medical supervision of the elderly
Medical examination is an important part of the choice of physical activity. This is due to a number of reasons:
- Some people should not do physical activity at all or only do it under the supervision of a doctor. A thorough medical examination can identify such people.
- The information obtained as a result of the medical examination is used in planning the physical activity program.
- A number of indicators obtained, for example, blood pressure, body fat, blood lipids, can be used to motivate bodybuilding.
- A comprehensive medical examination, in particular of physically healthy people, allows you to subsequently detect abnormalities in the state of health.
- men 40 and older;
- women 50 and older; people of any age at increased risk.
- Contraindications to exercising in the gym: diseases in the acute and under the acute stages; progressive diseases of the nervous system; circulatory failure II and III degree; aneurysm of the heart and large vessels; Ischemic heart disease with severe attacks of angina pectoris; frequent internal bleeding (stomach ulcer and duodenal ulcer, hemorrhoids, gynecological and other diseases).
In middle and old age, the following types of physical exercises are used for recreational purposes: UGG, dosed walking, health path, swimming, cycling, exercises with weights.
The intensity of the exercise should be reduced compared to younger people. Limitations are usually associated with one or another functional deviation in the state of health.
In the initial period, it is advisable to conduct classes with a moderate load 3-4 times a week for 35-45 minutes, and after 1.5-3 months. it can be increased up to 45-50 minutes. A further increase in the duration of classes is undesirable - it is better to increase the number of classes to 5-6 per week. The density of the load in the classroom is also important. The functional state in the process of training is controlled by the pulse, respiratory rate and subjective sign of fatigue (the pulse should not exceed the value obtained by subtracting the number of years from 220). Classes should take place with breaks for rest, walking, relaxation exercises, etc. Exercises for holding the breath, straining, with sudden movements, especially swinging, head rotations, with a prolonged tilt of the head down, jumping (or leaping), etc. should be excluded.
In accordance with the theory and practice of physical culture, classes are built in the form of a lesson, consisting of three parts: introductory, main and final. The introductory part includes general developmental exercises, walking, running; it's essentially a warm-up.
The main part, depending on the goal, includes general developmental exercises, elements from various sports, etc. the final part of the lesson aims to gradually restore the function of the cardiorespiratory system, includes walking, breathing exercises, relaxation exercises, stretching, etc.
Muscles and muscle groups are surrounded by connective tissue membranes - fascia. Fasciae also cover entire areas of the body and limbs and are named after these areas (fascia of the chest, shoulder, forearm, thigh, etc.). Fascial sheaths are composed of loose dense fibrous connective tissue, therefore they are very durable and perfectly resist mechanical stretching during muscle contraction. The great Russian surgeon and anatomist NI Pirogov called the fascia "the soft skeleton of the body."
Introduction …………………………………. ………………… ... …… ..p. 2-4
Main functional properties of muscles ……………… ..... …… .p. 5
Muscle work and strength ………………………………………. ……… ..p. 5-6
Muscle tone …………………………………………. ……. pp. 6-7
Muscle mass and muscle strength in different
age periods ………………………………………………. …… p. 7-8
Age features of speed, accuracy
movements of endurance ……………… ... ………………… ... ………… .p. 9-10
The influence of physical activity on the body ……………… ....… p. 10-15
Fatigue with different types of muscle
work, his age characteristics ………………………… .... …… ..p. 15-16
Development of motor skills,
improvement of coordination of movements with age ... ... ... ... ... p. 16-18
The motor regime of students
and harm to hypodynamia ……………… ... ……………………………….… ..p. 18-22
Conclusion ………………………… .. ………………. ……………… p. 23
References …………………. ………………… .. ………… ... p. 24
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The increase with age in the maximum frequency of movements is explained by the increasing mobility of nervous processes, which ensures a faster transition of antagonist muscles from a state of excitement to a state of inhibition and vice versa.
The fidelity of movement reproduction also changes significantly with age. Preschoolers 4-5 years old cannot perform fine precise movements that reproduce a given program both in space and in time. At primary school age, the ability to accurately reproduce movements according to a given program increases significantly. From the age of 9-10, the organization of precise movements is similar to that of an adult. In the improvement of this motor quality, an essential role is played by the formation of the central mechanisms of the organization of voluntary movements associated with the activity of the higher parts of the central nervous system. In the process of a child's development, the ability to reproduce a given amount of muscle tension also changes. Accuracy of reproduction of muscle tension is low in children of preschool and primary school age. It rises only by the age of 11-16.
Over a long period of ontogenesis, one of the most important qualities is also formed - endurance (a person's ability to continuously perform this or that type of mental or physical (muscular) activity without reducing their effectiveness). Endurance for dynamic work is still very low at 7-11 years old. From 11 to 12 years old, boys and girls become more resilient. Studies show that walking, running slowly, and skiing are good means of developing endurance. By the age of 14, muscular endurance is 50-70%, and by the age of 16, about 80% of an adult's endurance.
Static stress endurance increases especially intensively in the period from 8 to 17 years. The most significant changes in this dynamic quality are noted in primary school age. In 11-14-year-old schoolchildren, the calf muscles are the most resilient. In general, endurance by the age of 17-19 is 85% of the adult level; it reaches its maximum values by the age of 25-30.
The rates of development of many motor qualities are especially high at primary school age, which, given the interest of children in physical education and sports, gives grounds to purposefully develop motor activity at this age.
The effect of physical activity on the body.
Muscular work is associated with significant energy costs, and therefore requires an increase in oxygen flow. This is achieved primarily by strengthening the activity of the respiratory system and the cardiovascular system. Increases in heart rate, systolic blood volume (the amount of blood ejected with each contraction), and blood minute volume. The increased blood supply provides blood not only to the muscles, but also to the central nervous system, which creates favorable conditions for its more intense activity. The intensification of metabolic processes during muscular work leads to the need for an increased release of metabolic products, which is achieved by an increase in the activity of the sweat glands, which also play an important role in maintaining a constant body temperature. All this testifies to the fact that physical activity, requiring increased muscular work, has an activating effect on the activity of physiological systems. In addition, the fulfillment of physical loads has a stimulating effect on the motor system, leads to the improvement of motor qualities. At the same time, the effectiveness of physical activity and their stimulating effect on the body can be achieved only when taking into account the age-related capabilities of the child's body, and above all the age-related characteristics of the musculoskeletal system, due to the degree of its structural and functional maturity.
In preschool age, when motor qualities, especially endurance, are still low, children cannot perform dynamic and static work for a long time. The ability to perform physical activity increases by primary school age. The increase in all indicators of muscle performance from 11 to 12 years old is especially pronounced. Thus, the volume of dynamic work (in kgm) performed by 10-year-old schoolchildren is 50% more than that of 7-year-olds, and at the age of 14-15 it is correspondingly more by 300-400%. The capacity of work from 7 to 11 years increases by only 30%, and from I to 16 years, more than 200%. Also rapidly, starting from the age of 12, the efficiency of schoolchildren under static stress is growing. At the same time, even among 15-16-year-olds, compared with 18-year-olds, the work capacity is 66-70%, while for 18-year-olds the volume of work and capacity are only approaching the lower limit of the same indicators in adults.
The age-related features of muscle performance, which are manifested during dynamic work and static stress, are inseparably associated with the characteristics of higher nervous activity and affect the training process and performance per unit of time. Thus, training for the same type of work requires twice as much time for 14-year-olds as for adults. The productivity of work per unit of time in 14-15-year-olds is 65-70% of the productivity of an adult. 15-18-year-old schoolchildren need rest time many times more than they spend on work. If a 20-year-old needs 2 times more time for rest than spent on work, then a 17-year-old, even trained for physical work, needs 4 times more.
There are certain differences in the muscle performance of students and in connection with their gender. The degree of fatigue when performing dosed dynamic muscular work in girls and boys within the same age group is the same. Strength, endurance and other indicators of muscle performance in girls, on average, are lower than in boys.
The characteristic features of the muscular performance of girls and girls affect the amount of work performed, especially hard work. Medium and heavy work is performed by girls and girls to a lesser extent and cause deeper changes in the body than boys and boys. It is more difficult for girls to adapt to the same job, and their capacity for work decreases faster than in boys.
The optimal age for the training influences of physical activity is from 9-10 to 13-14 years old, when the main links of the motor system and motor qualities are most intensively formed. Adolescence has great potential for improving the motor system. This is confirmed by vivid examples of the achievements of adolescents in such sports as rhythmic and artistic gymnastics, figure skating, as well as in ballet, dancing, where we observe surprisingly high manifestations of movement coordination. At the same time, it should be borne in mind that this age is characterized by significant changes in the functioning of the body associated with puberty. Therefore, for adolescent boys and girls who do not systematically go in for sports, it is necessary to dose the loads associated with the manifestation of maximum strength and endurance. Taking into account the functional capabilities of the child's body, physical activity has extremely beneficial effects on the physical and mental development of the child.
Physical exercises are an effective means of improving the human motor apparatus. They are at the heart of any motor skill and skill. Under the influence of exercises, the completeness and stability of all forms of human motor activity are formed. The physiological meaning of the exercise is reduced to the formation of a dynamic stereotype. In the initial period of the exercise, widespread excitement takes place in the cerebral cortex. A large number of muscles are involved in the active state, the student's movements are awkward, fussy, chaotic. At the same time, numerous muscle groups are reduced, which often have nothing to do with this motor act. As a result, inhibition develops, muscle performance decreases.
During exercise, widespread cortical excitement is concentrated in a limited group of muscles directly associated with this exercise or movement act, a focus of stationary excitation is formed, which makes movements clearer, more free, coordinated and more economical in terms of time and energy consumption.
At the final stage, a stable stereotype is formed, as the exercises are repeated, the movements become automated, well coordinated, and they are performed only due to the conjugation of those muscle groups that are necessary for a given motor act.
Systematic training increases the power and efficiency of the muscles in the body. This increase is achieved due to the development of the muscles involved in this work (the muscles being trained increase in volume, and therefore their strength increases), as well as as a result of changes that the cardiovascular and respiratory systems undergo.
Breathing in trained people at rest is more rare and reaches 8-10 per minute compared to 16-20 in untrained people. A decrease in the respiratory rate is accompanied by a deepening of breathing, therefore, ventilation of the lungs does not decrease.
During muscular work, pulmonary ventilation can reach up to 120 liters per minute. In trained people, ventilation is increased due to deepening breathing, while in untrained people, due to increased breathing, which remains shallow. Deep breathing of trained people contributes to better blood oxygen saturation.
In trained people, there is a decrease in the number of heart contractions, but the systolic (stroke) and minute blood volume increases with a slight increase in heart rate. In untrained people, the minute volume increases due to increased cardiac activity with a slight increase in systolic volume.
Fitness, which can be achieved by means of physical education of a child, leads not only to the physical improvement of children and the strengthening of their health, it is reflected in the development of higher nervous functions and mental processes, contributes to the harmonious development of the personality.
Fatigue with various types of muscle work, its age characteristics.
Exercise training is essential for reducing muscle fatigue ... Fatigue is called a temporary decrease in the working capacity of the whole organism, its organs and systems, which occurs after prolonged intense or short-term excessively intense work. Physical fatigue occurs after prolonged and intense muscular exertion. With pronounced fatigue, a prolonged shortening of the muscles develops, their inability to completely relax - contracture. A decrease in physical performance is associated with both changes in the muscle itself and changes in the central nervous system. The role of the central nervous system in the development of muscle fatigue was first established by I.M.Sechenov, who showed that the restoration of the working capacity of one hand after prolonged lifting of a load is significantly accelerated if, during the rest period, work with the other hand is performed. In contrast to simple rest, such rest is called active rest and is considered as proof that fatigue develops primarily in the nerve centers. The role of the central nervous system in the development of fatigue is also evidenced by data on an increase in performance under the influence of positive emotions and motivations.
The connection between fatigue and the activity of the central nervous system and peripheral apparatus indicates that the degree of their maturity determines physical performance in childhood. The younger the child, the faster physical fatigue sets in during muscular exertion. A very low level of energy metabolism in the muscles of newborns and infants, as well as the immaturity of the nervous system, determine their rapid fatigue. One of the significant turning points in the development of physical performance is the age of 6 years, which is characterized by high energy capabilities of skeletal muscles and pronounced changes in the structural and functional maturation of the central nervous system. At the same time, in children of preschool and primary school age, the final differentiation of skeletal muscles has not yet occurred. Physical performance at primary school age is 2.5 times less than that of 15-16-year-olds. An important turning point in the development of physical performance is the age of 12-13 years, when significant changes in the energy of muscle contraction occur. An increase in physical performance at this age affects the indicators of muscular endurance, in the ability to endure prolonged loads with a lesser degree of fatigue. Correctly dosed physical activity, taking into account the degree of structural and functional maturity of the child's physiological systems at different age periods, prevents the development of prolonged fatigue. The alternation of mental and physical labor contributes to an increase in the efficiency of students.
Development of motor skills, improvement of movement coordination with age.
A newborn child has erratic movements of the limbs, trunk and head. Coordinated rhythmic flexion, extension, adduction and abduction are replaced by arrhythmic, uncoordinated isolated movements.
The motor activity of children is formed by the mechanism of temporary connections. An important role in the formation of these connections is played by the interaction of the motor analyzer with other analyzers (visual, tactile, vestibular).
An increase in the tone of the occipital muscles allows a child of 1.5-2 months, laid on his stomach, to raise his head. At 2.5-3 months, hand movements develop in the direction of a visible object. At 4 months, the baby turns from back to side, and at 5 months, rolls over onto his stomach and from stomach to back. At the age of 3 to 6 months, the child prepares for crawling: lying on his stomach, raises his head and upper body higher and higher; by 8 months he is able to crawl fairly long distances.
At the age of 6 to 8 months, thanks to the development of the muscles of the trunk and pelvis, the child begins to sit up, get up, stand and lower, holding on to the support with his hands. By the end of the first year, the child is free to stand and, as a rule, begins to walk. But during this period, the steps of the child are short, uneven, the position of the body is unstable. Trying to maintain balance, the child balances with his arms, puts his legs wide. Gradually, the stride length increases, by the age of 4 it reaches 40 cm, but the strides are still uneven. From 8 to 15 years old, stride length continues to increase and the pace of walking decreases.
At the age of 4-5 years, in connection with the development of muscle groups and the improvement of coordination of movements, more complex motor acts are available to children: running, jumping, skating, swimming, gymnastic exercises. At this age, children can draw, play musical instruments. However, preschoolers and younger schoolchildren, due to the imperfection of the regulatory mechanisms, find it difficult to master the skills associated with the accuracy of hand movements and the reproduction of given efforts.
By the age of 12-14, there is an increase in the accuracy of throws, throwing at the target, and the accuracy of jumps. However, some observations show a deterioration in the coordination of movements in adolescents, which is associated with morphofunctional transformations during puberty. A decrease in endurance in high-speed running in 14-15-year-old adolescents is also associated with puberty, although the running speed increases significantly by this age.
