Children have largely developed regulatory mechanisms aimed at maintaining the necessary daily physical activity. According to the observations of K. Smirnov and co-authors (1972), children of preschool age with artificial restriction of motor activity for some time significantly increased it in the rest of the day.

Attempts to establish indicative norms of motor activity have been made repeatedly.

The level of physical activity at school age is significantly

to a lesser extent due not to the age-related need for it (kinesophilia), but to the organization of physical education at school, involving children in organized and independent activities during extracurricular time

The Research Institute of Physiology of Children and Adolescents of the Academy of Pedagogical Sciences of the USSR recommended a daily two-hour amount of physical activity for schoolchildren, which could compensate for the need for movement. Within 2 hours, a sufficient physiological load can also be achieved (depending on the content of the exercises and the magnitude of the load during extended breaks, the motor density of physical education lessons and additional classes during extracurricular time). The International Council for Physical Education and Sports in 1968 issued a special manifesto on sports, which determined the daily duration of physical exercises at school. According to experts, it should be from 1/6 to 1/3 of the total study time. Thus, scientists agree that the optimal amount of weekly motor activity should be 12-14 hours with sufficient physiological load.

The norm of physical activity in childhood is such a value that fully satisfies the biological needs for movement, corresponds to the capabilities of a growing organism, contributes to its development and health promotion.

Achieving such a volume of physical activity by students of secondary schools is most often an impossible task.

In most developed countries, as a rule, 3-4 compulsory physical training sessions per week are provided. The content of the classes includes general developmental exercises, sports and outdoor games, swimming, dance exercises. Physical education programs are extremely varied. The teacher is given the right to use a variety of means of physical education and additional physical activity, depending on the individual level of physical fitness of the students. So, in most schools in the United States, in addition to compulsory lessons, weekly competitions and three additional classes outside of school hours are held.

The comprehensive physical education program adopted in Ukraine, in addition to two or three compulsory lessons per week, provides for additional and optional classes, daily physical exercises. In general, children should be physically active for about two hours a day. But even under the most favorable conditions, a general education school is not able to provide the necessary amount of physical activity, therefore, the actual specially organized physical activity is limited to 3-4 hours a week for the bulk of schoolchildren, which is 30% of the hygienic norm.

Children attending the Youth Sports School are busy training from 8 to 24-28 hours a week, which is several times higher than the weekly load of those involved in general education schools.

Excessive motor activity is referred to as hyperkinesia. Recently, early sports specialization has become widespread, causing hyperkinesia. Studies by scientists have shown that hyperkinesia causes a specific complex of functional disorders and clinical changes. This condition is accompanied by dangerous changes in the central nervous system and neuroregulatory apparatus of children. There is a depletion of the sympathetic-adrenal system, a protein deficiency and a decrease in immunity (Balsevich, Zaporozhanov, 1987; Sukharev, 1991; and others).

The criterion for the optimal rate of motor activity is the reliability of the functioning of all body systems, the ability to adequately respond to changing environmental conditions. Violation of homeostasis and inadequacy of reactions indicate going beyond the optimal norm, which ultimately leads to poor health

There is a certain relationship between the reaction of the body and daily physical activity. The problem of motor activity rationing is quite complex, and many aspects must be taken into account when solving it.

Hygienic norm of motor activity per day (locomotion, thousand steps)

5-6 years old - 11.0-15.0

7-10 years - 15.0-20.0

11-14 years old - 10.0-25.0 (boys), 17.0-23.0 (girls)

15-17 years old - 15.0-30.0 (boys), 20.0-15.0 (girls)

The main organizational and methodological principle of the implementation of physical education is the differentiated use of various means of physical culture, taking into account age and gender characteristics, health status, degree of physical development and level of physical fitness. In accordance with them, schoolchildren are divided into three medical groups: the main (without deviations or with minor deviations in the state of health with sufficient physical development - they are engaged in the curriculum of physical education in full), preparatory (they have minor deviations in the state of health or are lagging behind in physical development - they are engaged in the curriculum of physical education with the condition of progressive mastering of skills and abilities, they are not allowed to sports training and competitions) and special (deviations in the state of health of a permanent or temporary nature, requiring limitation of physical activity - are engaged in a special program).

Motor activity is the sum of movements performed by a person in the process of life. Motor activity of children and adolescents is conditionally divided into three parts:

Which takes place in the process of physical education;

What happens in the process of learning, socially useful and labor activity;

Spontaneous physical activity during free time.

These components, complementing each other, provide a certain level of daily physical activity of schoolchildren of different age and sex groups.

The influence of physical activity on the health of schoolchildren. In the modern elementary school, mental activity is among the most difficult in children, whose cells of the cerebral cortex still have relatively low functional capabilities, and therefore heavy loads can cause their exhaustion. Training requires long-term storage of a forced working posture, creates a significant load on the musculoskeletal system and the muscular system of children. It is noted that there is a close relationship between the daily physical activity and the health of schoolchildren.

lack of movement, or hypokinesia, causes numerous morphological and functional changes in the body. The complex of these changes refers to pre-pathological and pathological conditions. The leading mechanism of hypokinesia is a violation of the regimes of self-regulation of physiological functions, a decrease in the functionality of the body, a violation of the activity of the musculoskeletal system, autonomic functions. Limitation of the number and volume of movements, due to the lifestyle and characteristics of professional activity, is also referred to as hypokinesia.

The main causes of hypokinesia in schoolchildren:

Restriction of motor activity associated with the mode of study and congestion of the curriculum;

Lack of systematic and sufficient physical exercise;

Chronic diseases and developmental deficits that limit motor activity.

One of the reasons for excessive motor activity, or hyperkinesia, is the early sports specialization of children. Hyperkinesis is characterized by a specific complex of functional disorders and changes in the state of health: the central nervous system and the neuroregulatory apparatus. At the same time, the sympathoadrenal system is depleted and the general nonspecific immunity of the body is reduced. Insufficient (hypokinesia) and excessive (hyperkinesia) motor activity adversely affect the health of the student.

The formation of the health of a particular student is provided by his usual daily motor activity, which includes a wide variety of forms, methods and means of physical education in certain hygienically rational proportions. Such motor activity is considered normal, it is steadily manifested in the process of life.

Methods for studying and evaluating motor activity. An informative and accurate method of hygienic assessment of both quantitative and qualitative activity is used to determine the magnitude of energy costs. Accurate, but also the most expensive is indirect calorimetry method, that is, determining the amount of oxygen consumed by the body. In hygienic practice, it is more often used calculation method for determining the values ​​of energy costs. To do this, study the following indicators:

Duration (minutes, hours or as a percentage relative to the day) of the motor component in the daily time budget;

The number of movements of the body in space (locomotion) per unit of time;

The sum of movements (locomotions), expressed as the distance traveled per day (in km).

Thanks to these indicators, fairly objective and reliable information about the nature and volume of a student's motor activity is obtained without the use of expensive equipment. To normalize motor activity, methods of indirect registration of heart rate, determination of the pulse "cost" of various types of activity, the total value of motor activity per day using telemetric systems are widely used.

Timing. In the hygiene of physical education, timekeeping is used to study and evaluate the daily rhythm of schoolchildren, and not to actually motor activity. The timing technique is based on recording the activities of a particular student at a certain time of the day or even during the day.

shagometry - calculation of locomotions of a schoolchild with the help of special devices (pedometers).

All hygienic standards of physical activity of schoolchildren are designed for a daily life cycle (24 hours), but sometimes for the hygienic characteristics of the physical activity of schoolchildren, long observation intervals are chosen - a week, a month, an academic quarter. However, this data can only be used for comparative evaluation of different variants of a student's motor activity.

Introduction

With age, the duration of physical activity, the child should gain physical activity up to 4-5 hours a day and its intensity will be low. Due to a number of age characteristics, the child is simply not yet capable of long-term work of medium and high intensity. Parents of elementary school students often ask: which of the sports sections is better for a child? If you do not have goals to conquer sports peaks, then at this age the sport is not so important.

However, I note that duration is only one of the characteristics of physical activity as a key factor. The type of physical activity, its intensity and multiplicity in the weekly cycle also matter.

Norms of physical activity in children

Motor activity is an activity that occurs as a result of a person’s muscle contraction and movement of his body / body parts / limbs in space as a result of the activation of metabolic processes. Simply put, it is a set of movements made in a certain period of time.

Hypokinesia is a forced decrease in the volume of voluntary movements due to the nature of labor activity; low mobility, insufficient motor activity (DA) of a person. The introduction of scientific and technological progress into production led to a redistribution of the load from large muscle groups to small muscles of the shoulder and forearm and was the reason for the decrease in the general DA in production - professional G. Professional groups emerged that perform work in a sedentary working position. Studies of the physical condition of people in "sedentary" professions showed that their physical performance is significantly reduced compared to people involved in physical culture and sports.

An effective technique for determining the volume of DA is counting the number of steps a person takes per work shift and per day - both on workdays and on weekends, as well as counting energy consumption. Workers of "sedentary" professions make 2008-2299 steps per work shift, while spending 801-879 kcal or 1.79-1.83 kcal/min. During the day on working days, the number of steps is 8023-10193, and on weekends 8928-11590 with energy consumption of 2195 kcal and 2698 kcal, respectively. These data indicate that, in terms of the volume of DA, the examined persons are at the lower limit of the “norm” characteristic of light manual labor workers. Lack of YES on working days is not compensated in free time, on weekends.

G. is one of the risk factors for pathological changes in the human body: diseases of the cardiovascular system, obesity, and disorders of the musculoskeletal system. Among the most dangerous consequences of small human DA, disorders in the cardiovascular system are distinguished. In persons working in the conditions of G., there is an increase in the heart rate (HR) at rest by 20%, a decrease in the contractile function of the heart muscle and the rate of its relaxation, and deterioration in the regulation of the heart rhythm. The adaptation of the heart to muscle loads occurs mainly due to an increase in heart rate with a relatively small increase in systolic blood volume, which is regarded as an uneconomical reaction that contributes to the rapid depletion of the functional reserve of the heart and has an unfavorable prognostic value in the development of diseases of the cardiovascular system.

The development of fatigue also depends on the level of physical fitness (FP) of a person. At the end of the work shift, the following are noted: an increase in the latent period of a simple visual-motor reaction in persons with a high and low level of general physical performance by 7 and 19%, respectively, compared with the initial values ​​(before work); decrease in the speed of information processing - by 10 and 21%; decrease in the endurance of the muscles of the hand - by 11 and 27%; decrease in the stability of clear vision - by 9 and 16%. The noted shifts in physiological functions during the shift indicate the developing fatigue of the worker's body, the depth and severity of which is much greater in people with a low level of AF.

Occupational G. significantly exacerbates the influence of other factors of the labor process on the human body, for example. neuro-emotional stress and monotony. Negative emotions acquire a pronounced intensity and character of stress. Against the background of a decrease in emotional resistance to stressful factors, negative emotions turn out to be difficult for a person to bear. G. in combination with a high level of neuro-emotional stress can cause a breakdown in a person's adaptive reactions. One of the effective means of increasing the ability to resist psycho-emotional stress should be an increase in physical activity.

For people with a low level of AF, physical education is necessary for 30–40 minutes 4–5 times a week for 10–12 months. For persons with an average level of AF, physical education is advisable for 20–30 minutes 3 times a week for 8–10 months. For persons with a high level of AF, classes are possible for 10-15 minutes 1-2 times a week.

In order to compensate for insufficient DA, the following are used:

equipping the workplace with ergonomic furniture;

industrial gymnastics;

group classes of a preventive orientation during the working day (regulated and lunch breaks);

individual lessons on exercise bikes during the working day and in free time;

group classes of rehabilitation and preventive orientation after the working day and on weekends;

self-study - running, skiing, swimming, etc.;

WHO has developed the "Global Recommendations on Physical Activity for Health" with the overall aim of providing policy-makers at the national and regional levels with guidance on dose-response relationships between frequency, duration, intensity, type and total the amount of physical activity needed to prevent noncommunicable diseases.

• Global recommendations for physical activity for health

The recommendations in this document are for three age groups: 5-17 year olds; 18-64 year olds; and people aged 65 and over. Below is a section with recommendations for each age group.

Age group: children and teenagers (5-17 years old)

For children and young people in this age group, physical activity includes play, competition, sports, travel, recreational activities, physical education, or planned exercise within the family, school, and community. To strengthen the cardiovascular system, musculoskeletal tissues and reduce the risk of non-communicable diseases, the following physical activity practices are recommended:

• Children and young people aged 5-17 should engage in moderate to vigorous physical activity daily for a total of at least 60 minutes.
• Physical activity lasting more than 60 minutes a day will bring additional health benefits.
• Most of your daily physical activity should be aerobics. High-intensity physical activity, including musculoskeletal exercises, should be done at least three times a week.

Age group: adults (18-64 years old)

For adults in this age group, physical activity includes recreational or leisure activities, moving activities (such as cycling or walking), occupational activities (i.e. work), household chores, games, competitions, sports or scheduled activities. within daily activities, family and society.

In order to strengthen the cardiopulmonary system, musculoskeletal tissues, reduce the risk of non-communicable diseases and depression, the following physical activity practices are recommended:

• Adults 65 years of age and older should engage in at least 150 minutes per week of moderate-intensity aerobic exercise, or at least 75 minutes per week of vigorous-intensity aerobics or similar moderate-to-high-intensity physical activity.
• Each aerobics session should last at least 10 minutes.
• For additional health benefits, adults in this age group should increase their moderate-intensity aerobic activity to 300 minutes per week, or 150 minutes per week for high-intensity aerobics or a similar combination of moderate-to-high intensity aerobics. .
• Adults in this age group with joint problems should do balance exercises to prevent the risk of falls 3 or more times a week.
• Strength exercises that involve major muscle groups should be done 2 or more days a week.
• If older people, for health reasons, cannot perform the recommended amount of physical activity, then they should engage in physical exercises, taking into account their physical abilities and health status.

Age Group: Seniors (65 years and older)

For adults in this age group, physical activity includes recreational or leisure activities, moving activities (such as cycling or walking), vocational activities (if the person continues to work), household chores, games, competitions, sports or scheduled activities in within daily activities, family and society.

The fact that physical activity improves physical features, increases efficiency, is well known. It is no less known that the scientific and technological revolution leads to a decrease in the coherence in the work of the muscular apparatus and internal organs due to a decrease in the intensity of proprioceptive impulses from skeletal muscles to the central apparatus of neurohumoral regulation (brain stem, subcortical nuclei, cortex of the cerebral hemispheres). At the level of intracellular metabolism hypokinesia (insufficient motor activity) leads to a decrease in the reproduction of protein structures: the processes of transcription and translation are disrupted (removal of the genetic program and its implementation in biosynthesis). With hypokinesia, the structure of skeletal muscles and myocardium changes. Immunological activity decreases, as well as the body's resistance to overheating, cooling, lack of oxygen.

Already after 7-8 days of immobile lying, functional disorders are observed in people; apathy, forgetfulness, inability to concentrate on serious activities appear, sleep is disturbed; muscle strength drops sharply, coordination is disturbed not only in complex, but also in simple movements; the contractility of skeletal muscles worsens, the physicochemical properties of muscle proteins change; calcium content decreases in bone tissue. Hypodynamia is especially detrimental to children. With insufficient physical activity, children not only lag behind their peers in development, but also get sick more often, have posture and musculoskeletal function disorders.

Prevention of hypokinesia is carried out with the help of physical exercises. During muscular work, not only the executive (neuromuscular) apparatus itself is activated, but also the work of internal organs, nervous and humoral regulation. Therefore, a decrease in motor activity worsens the condition of the body as a whole. Both the neuromuscular system and the functions of internal organs suffer.

The substantiation of a rational motor regimen for children, the regulation of physical activity is one of the most difficult problems. Both hypokinesia and the phenomenologically opposite functional state, hyperkinesia, have their costs. Therefore, the need for strict differentiation of the magnitude of the load depending on gender and age, as well as the level of physical development of schoolchildren, follows from the very concept of individual adequacy of the load.

In most economically developed countries, as a rule, no more than 3-4 compulsory physical training lessons per week are provided. Its basis is general developmental exercises, sports and outdoor games, swimming, dance exercises. Physical education programs are extremely varied. The teacher is given the right to use a variety of means of physical education and additional physical activity, depending on the individual level of physical fitness of the students. So, in most US schools, in addition to compulsory lessons, weekly competitions and three extra classes are held after school hours.

The comprehensive physical education program adopted in our country, in addition to two compulsory lessons per week, provides for additional and optional classes, physical exercises during the school day. In general, children should be physically active for about two hours a day.

The motor activity of children with an average daily number of locomotions exceeding 30,000 steps exceeds the evolutionarily acquired biological need for movement. At the same time, the number of locomotions within 10,000 steps per day is insufficient. The deficit of the daily need for movements in this case ranges from 50 to 70% (Table 1).

Table 1

Characteristics of physical activity of schoolchildren aged 11-15

Activity level	Number of locomotions per day (thousand steps)	The ratio of the number of movements performed to natural, biologist. needs (%)	Total volume (h)
			during the week
		Shortage 50-70%
Moderate		Shortage 20-40%
		Conformity
Maximum		Excess by 10-30%	20 or more	1000 or more

Approximate age norms of daily physical activity, providing a normal level of vital activity, improvement of somatic, vegetative and natural protective functions of the body, reduced to low-intensity cyclic work (running, walking), range from 7.5 to 10 km for children 8-10 years old, from 12 to 17 km for 11-14 year olds of both sexes. The daily range of motion in girls aged 15-17 is significantly less than in boys (Table 2).

table 2

Approximate age norms of the daily

motor activity

Age group (years)	Number of locomotions (thousand)	Approximate mileage	Duration of work associated with muscular effort (per hour)
15-17 (boys)
15-17 (girls)

The data given in this table can serve as nothing more than conditional indicative norms for schoolchildren. The regulation of physical activity in terms of volume and intensity should be strictly individual.

Physical exercises play a big role in the formation of posture. Posture is the habitual position of the body at rest (standing, sitting) and when moving (walking, running). It is formed already in early childhood, when the child begins to sit, stand and walk independently, that is, when he develops normal curves of the spine. However, the possibility of their deformation persists not only in preschool age, but also throughout the school years due to improper sitting at a desk, asymmetrical carrying of weights, and imitating the incorrect posture of elders.

Correct posture is a normal posture when standing and sitting: the shoulders are deployed and are at the same level of the shoulder blade, they do not protrude, they are located symmetrically, the stomach is tucked up, the legs in a standing position are straightened at the knees. The natural curves of the spine allow you to maintain a normal posture. Physiologically correct posture ensures the optimal functioning of the respiratory, circulatory, digestive, and musculoskeletal systems. Correct posture facilitates coordination of movements.

To form a correct posture, preventive measures are necessary to prevent its violation. These, first of all, include the exclusion of monotonous, long-term postures, carrying weights in one hand, sleeping in a soft bed.

In case of violation of posture, the configuration of the curves of the spine changes, the head is lowered, the shoulders are brought together, the shoulder blades are asymmetrical, breathing, blood circulation, digestion, coordination of movements, and just appearance deteriorate.

The spinal column has 4 bends: forward bulge (cervical and lumbar lordosis) and posterior bulge (thoracic and sacral kyphosis) , which are formed by the age of 6-7 and are fixed by the age of 18-20.

Depending on the severity of the curves of the spine, there are several types of posture:

normal - moderately pronounced curvature of all parts of the spine;

straightened - slightly pronounced curvature of the spinal column. The back is sharply straightened, the chest protrudes somewhat forward;

stooped - a pronounced curvature of the spinal column in the thoracic region. The cervical curve is markedly increased and the lumbar curve is reduced. The chest is flattened, the shoulders are brought forward, the head is lowered;

Lordotic posture - a pronounced curvature in the lumbar region with a decrease in the cervical bend. The abdomen is bulging or sagging;

· kyphotic - compensatory strengthening of thoracic kyphosis due to excessive curvature simultaneously in the cervical and lumbar spine. In this case, as a rule, the reduction of the shoulders forward is noticeable, the protrusion of the head, the elbow and knee joints are usually half-bent.

Lateral curvatures of the spinal column to the left or right of the vertical line form a scoliotic posture, characterized by an asymmetric position of the body, in particular, the shoulders and shoulder blades. Scoliosis is functional in nature, regardless of the severity. Being a violation of posture, they can affect blood circulation and breathing.

The type of posture may correspond to the profession, birth defects or negative ergonomic influences (the height of the chair - table when eating, writing, reading, lighting, forced working posture). It has been proven that posture changes in the process of purposeful development of underdeveloped muscles, which contributes to its correction and prevention.

Physical exercises aimed at maintaining the correct posture are selected in such a way as to fix the usual correct position of the head, shoulders, torso, develop the strength of the muscles of the torso and neck, upper and lower extremities. Strengthening the correct posture reflex is facilitated by exercises with holding various objects on the head, exercises performed on a reduced support, coordination exercises, and static postures. It is necessary to constantly adjust the position of the body when performing exercises, to create in the child a clear idea of ​​​​the correct posture (in particular, about the adverse consequences of its violations), a persistent feeling of discomfort with incorrect posture. This will allow you to constantly monitor the maintenance of the correct posture in the sitting position, and when walking, and during physical exercises.