Mental and physical labor of a person. Brainwork

Introduction

Labor physiology is a science that studies the functioning of the human body during work.

Its task is to develop principles and norms that contribute to the improvement and improvement of working conditions, as well as standardization of labor.

Physiology is the science of the life activity of the body and its individual parts - cells, organs, functional systems. Physiology studies the mechanisms of the functions of a living organism (growth, reproduction, respiration, etc.), regulation and adaptation to the external environment. In particular, she studies the regulatory and integrating role of the nervous system in the body.

From a physiological point of view, labor is an expenditure of physical and mental energy of a person, but it is necessary and useful to a person. And only in harmful conditions or when there is excessive strain on a person’s strength, the negative consequences of labor can manifest themselves in one form or another. Work is usually characterized by heaviness and tension.

The severity of labor is a characteristic of the labor process, reflecting the predominant load on the musculoskeletal system and the functional systems of the body (cardiovascular, respiratory, etc.) that ensure its activity. The severity of labor is characterized by physical dynamic load, the mass of the load being lifted and moved, the total number of stereotypical working movements, the magnitude of the static load, the nature of the working posture, the depth and frequency of body tilt, and movements in space.

Labor intensity is a characteristic of the labor process, reflecting the load primarily on the central nervous system, sensory organs, and emotional sphere of the worker. Factors characterizing labor intensity include: intellectual, sensory, emotional stress, the degree of monotony of workload, and work mode.

Ergonomics is a science that studies human functionality in labor processes from the point of view of anatomy, anthropology, physiology, psychology and hygiene in order to create tools and working conditions, as well as technological processes that best meet the requirements of the human body.

Ergonomics and production aesthetics are integral parts of production culture, i.e. a set of labor organization measures aimed at creating a favorable working environment. Improving the production culture is based on the requirements of the scientific organization of labor. Production culture is achieved by proper organization of work processes and relationships between employees, improvement of workplaces, and aesthetic transformation of the working environment.

There is a distinction between mental and physical work.

Physical work

As for physical labor, quite objective criteria for assessing severity have been defined for it, these are energy consumption.

All types of physical work are performed with the participation of muscles, which, when contracting, perform work in the physiological sense of the word. Replenishment of muscle energy occurs due to the consumption of nutrients that are constantly supplied to the bloodstream. The same blood flow carries away waste substances from the muscles - oxidation products. The main source of energy is the oxidation of glycogen by oxygen, also contained in the blood. Glycogen is a polysaccharide formed by glucose residues. It is deposited in the cytoplasm of liver and muscle cells. When there is a lack of glucose in the body, glycogen is broken down by enzymes into glucose, which enters the blood.

Physical work is usually divided into three groups according to its severity. This division is based on oxygen consumption as one of the objective indicators of energy consumption available for measuring. In this regard, work is distinguished: light, medium and heavy.

Light work includes work performed while sitting, standing or associated with walking, but without systematic stress, without lifting and carrying heavy objects. These are works in clothing production, precision instrument making and mechanical engineering, printing, communications, etc.

The moderate category includes work involving constant walking and carrying small (up to 10 kg) weights, and performed while standing. This is work in mechanical assembly shops, mechanized open-hearth, rolling, foundry, forging, thermal shops, etc.

The heavy category includes work associated with systematic physical stress, as well as with constant movement and carrying of significant (more than 10 kg) weights. These are blacksmith works with hand forging, foundry works with manual filling and pouring of flasks, etc.

To increase the delivery of oxygen and nutrients, as well as to remove their oxidation products, the cardiovascular system increases blood flow. This is done in two ways: by increasing the heart rate and increasing the volume of each heart contraction.

So, the main physiological reactions of the body to physical work are increased heart rate, increased blood pressure, increased breathing and increased pulmonary ventilation, changes in blood composition, and increased sweating. Changes gradually increase, reaching a certain level at which the increased work of organs and systems is balanced with the needs of the body.

After cessation of work, a recovery period begins when the altered functions gradually return to normal. But the recovery time for various functions is not the same:

pulse, pressure, respiratory rate and pulmonary ventilation are restored in 10-15 minutes;

blood composition, etc. - in 45-50 minutes.

This is due to the fact that during intense work the body’s internal resources are mobilized, non-working tissues and organs are depleted of oxygen and nutrients, as well as the reserves of the muscle cells themselves are absorbed, which, due to these internal reserves, can work for some time without consuming oxygen (the so-called anaerobic phase of muscle work). To replenish these reserves during rest, the body continues to consume increased amounts of oxygen.

If, during prolonged hard work and when all the body's resources are mobilized, the delivery of the required amount of oxygen and nutrients is not ensured, muscle fatigue occurs.

Muscles work not only when a person moves weights, but also when he holds them in place, or holds the weight of his own body or its individual parts (torso, arms, head).

In this regard, the main indicators of the severity of the labor process are:

· weight of cargo lifted and moved manually;

· stereotypical labor movements;

· working posture;

· body tilts, movement in space.

A forced and even more uncomfortable body position, even in the case of light work, can lead to rapid fatigue, because static load on the same muscle groups is more tiring. The working posture can be free, uncomfortable, fixed or forced. Free poses include comfortable sitting postures, with the possibility of changing the working position of the body or its parts. Fixed working posture is the impossibility of changing the relative position of various parts of the body relative to each other. Similar postures are encountered when performing work related to the need to distinguish small objects during work. The most rigidly fixed working postures are for representatives of those professions who have to perform their main production operations using optical magnifying devices - magnifiers and microscopes. Uncomfortable working postures include postures with a large bend or turn of the torso, with arms raised above shoulder level, and with inconvenient placement of the lower extremities. Forced postures include working postures lying down, kneeling, squatting, etc.

Physiologists distinguish several stages in the work process:

· at the beginning, performance increases (workability);

· having reached a maximum, labor productivity remains at this level for more or less a long time (stable work);

· then a gradual decrease in performance (fatigue) occurs.

b Organizing short breaks at the end of maximum performance reduces fatigue and increases overall labor productivity.

In addition to physiological changes in the form of fatigue, various types of physical stress can also cause some pathological phenomena in the body, i.e. diseases:

· prolonged work in an uncomfortable position can lead to curvature of the spine to the side (scoliosis) or forward (kyphosis);

· with prolonged standing or walking under load - flat feet or varicose veins of the lower extremities;

· constant static tension or monotonous movements during hard intensive work lead to neuromuscular diseases (inflammation of the tendons, neuroses, lumbago, etc.);

· frequent and prolonged tension of the same groups of abdominal muscles - hernias;

· tension in the organs of vision - myopia.

ь The female body is especially sensitive to the adverse effects of various harmful factors. In particular, with physical activity over 15 kg, prolapse of the uterine body is observed. Constant static and dynamic load on the spine and legs in women can lead to disruption of the shape and function of the feet, changes in the sacropelvic angle. Women whose working conditions are associated with vibration may experience spontaneous abortions, premature births, and toxicosis in the first and second halves of pregnancy. Of great practical importance is the influence of chemical substances on the specific functions of the female body, even when their content does not exceed the maximum permissible concentrations (MPC).

The term "health" in the constitution of the World Health Organization (WHO) is defined as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." In this sense, the health of the population is influenced by working and living conditions, housing conditions, wage levels, food supply and quality, the state of medical care, climatic and geographical and other social and hygienic factors.

Scientific and technological progress has a significant impact on the professional structure of the working population. The number of people employed increases every year mental labor.

In many professions of predominantly physical labor, the share of the intellectual component is increasing. Drawing a clear line between the physical and mental forms of people’s work is becoming increasingly difficult.

Meanwhile, the generally accepted division of labor into physical and mental still remains in force. It is customary to refer to mental work as work related to the process of receiving, processing and storing information, on the basis of which various kinds of theoretical and practical problems are solved, which requires predominantly straining the functions of perception, attention, memory, thinking and the emotional-volitional sphere of a person.

Currently, there are two main groups of forms of human mental (intellectual) activity: in the sphere of material production and beyond.

The first includes engineering professions associated with the design of the production process (for example, designers), as well as with the performance of operational (engineers, technicians, foremen, operators), accounting (accountants, statisticians) and management (managers of enterprises, associations) functions.

The second - professions engaged in the field of scientific activity (scientists), applied knowledge (teachers, doctors, psychologists), literature and art (writers, actors, painters).

All forms of intellectual work are based on the internal mental activity of a person, which has as its material substrate the work of the brain. The predominant load on the central nervous system and insignificant, in comparison with physical labor, muscle activity determine the relative energy efficiency of intellectual activity.
Nevertheless, all forms of mental work are accompanied by certain energy expenditures, causing fatigue in working people. At the same time, different professions require different expenditure of energy resources of the human body.

Depending on the amount of energy consumption, intellectual work can be, by analogy with the severity of physical work, of varying degrees of intensity, which is determined by quantitative and qualitative indicators of loads on human mental functions.

The first include: the duration of concentrated observation (as a percentage of the shift time), the number of information signals received by the employee, the size of objects of labor, their number and many others.

The second is the level of emotional and volitional tension, personal risk, responsibility for the safety of others, the degree of complexity of the production tasks being solved.

The shift schedule is also taken into account, on the basis of which work with alternating shifts, including night shifts, typical, in particular, for the majority of maritime professions.

As you know, the life of every person is subject to a certain rhythm, which manifests itself in communication, knowledge, and work. In other words, human activity is organized in time, forming a unified system of daily, weekly, monthly and long-term rhythms. They manifest a strict biological periodicity of the physical and mental functions of all living things, caused by natural cyclical phenomena (the change of day and night).

Disruption of this natural rhythmic process causes tension in the body's regulatory systems (primarily the brain), which are responsible for the restructuring of its temporal organization. Thus, a work regime imposed on a person for a long time, which does not correspond to normal biological rhythms, is one of the factors that increases workload.

Any profession requires a person to master certain action programs. And in this sense, the main features of intellectual work include complexity and variability or excessive simplification of such programs associated with the technicalization of modern production.

Concept "program complexity" may include, firstly, the number of signals received by the employee from various objects of the social and industrial environment surrounding him and carrying information about their properties and connections.
Secondly, these can be various ideas and concepts that a person operates in the process of practical activity. The more different kinds of components there are in a performer’s program of labor actions, the more complex the content side of mental work.

For example, The captain’s labor functions include a variety of mental work operations: plotting the ship's course on a map, assessing the navigation situation, making non-standard decisions in difficult operational situations (accident, accident, injury), direct participation in resolving interpersonal conflicts between crew members and many others.

Representatives of creative professions are also guided by complex action programs(scientists, architects, designers) who establish new connections between phenomena and objects of the real world, discovering new patterns. Creative work is associated with high emotional stress on the performer, which often leads to large expenditures of energy and the development of significant fatigue and overwork. Therefore, creative professions are among the most stressful.

All the examples discussed above give an idea of "program changes" labor actions as the second important feature of many types of mental activity. The ability to restructure existing programs and create new ones depending on the type of work is not always possible. For example, the professions of ship radio operators, telegraph operators (when working with a key), and accountants are, as a rule, characterized by constant action programs. This is one of the leading factors of monotony - monotony of activity. The more pronounced the uniformity of work functions, the higher the degree of monotony of labor and its intensity.

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Ministry of Education and Science of the Russian Federation

Rostov State Economic University "RINH"

Faculty of Information and Management

Rabstract

in the discipline "Life Safety"

on the topic: "Mental and physical labor of a person"

Completed by: student of group 311

Avksentyev M.A.

Checked by: Belokopytov I.A.

Rostov-on-Don 2010

Introduction

1. Human functional activity and the relationship between physical and mental activity

2. Means of physical culture that provide resistance to mental and physical performance

3. Fatigue during physical and mental work. Recovery

Conclusion

List of used literature

Introduction

Even in ancient times, doctors and philosophers believed that it was impossible to be healthy without physical exercise. The ancient Greek philosopher Plato called movement “the healing part of medicine,” and the writer and historian Plutarch called it “the storehouse of life.” Do we always appreciate that this “storehouse” is not emptied? Unfortunately no.

At various stages of development, a person moves further and further away from physical labor. So previously, the share of manual labor in the production process was 95%, the rest was accounted for by the use of a few steam engines and pack animals. Today, in the age of the scientific and technological process, humanity has practically moved away from the large-scale use of manual labor, thereby “giving a free hand” to the so-called diseases of the century.

Many people try to cut themselves off from exercise entirely, thinking that the less exercise they do, the healthier they will become. Many knowledge workers and students try to reduce physical activity, thereby undermining their health. They try in every possible way to obtain certificates of release and at the same time find support from their parents and, worst of all, from doctors. body psyche mental fatigue

It is known that constant neuropsychic stress and chronic mental fatigue without physical relaxation cause severe functional disorders in the body, decreased performance and the onset of premature old age.

It has been found that regular exercise reduces the amount of cholesterol in the bloodstream, which contributes to the development of atherosclerosis. At the same time, the anticoagulation system is activated, preventing the formation of blood clots in the vessels. Due to a moderate increase in the total content of potassium ions in the blood and a decrease in sodium ions, the contractile function of the myocardium is normalized. The adrenal glands release the “good mood hormone” into the blood. If we take all this into account, it is not surprising that, for example, in the Swiss city of Blatendorf, located in the mountains, where residents can only walk and run, not a single case of cardiovascular disease has been recorded.

1. Human functional activity and the relationship between physical and mental activity

Human functional activity is characterized by various motor acts: contraction of the heart muscle, movement of the body in space, movement of the eyeballs, swallowing, breathing, as well as the motor component of speech and facial expressions.

The development of muscle functions is greatly influenced by the forces of gravity and inertia, which the muscle is constantly forced to overcome. The time during which muscle contraction unfolds and the space in which it occurs play an important role.

It is assumed and proven by a number of scientific works that labor created man. The concept of “labor” includes its various types. Meanwhile, there are two main types of human labor activity - physical and mental labor and their intermediate combinations.

Physical labor is “a type of human activity, the characteristics of which are determined by a complex of factors that distinguish one type of activity from another, associated with the presence of any climatic, production, physical, information and similar factors” Balsevich V.A., Zaporozhanov V.A. . Human physical activity. -Kyiv. .Health, 1987. - P. 102. . Performing physical work is always associated with a certain severity of labor, which is determined by the degree of involvement of skeletal muscles in the work and reflects the physiological cost of primarily physical activity. According to the degree of severity, work is classified into physically light, moderate, hard and very hard work. The criteria for assessing the severity of work are ergometric indicators (amount of external work, moved loads, etc.) and physiological (levels of energy consumption, heart rate, other functional changes).

Mental work is “a person’s activity to transform the conceptual model of reality formed in his mind by creating new concepts, judgments, conclusions, and on their basis - hypotheses and theories” Balsevich V.A., Zaporozhanov V.A. Human physical activity. -Kyiv. .Health, 1987. - P. 105. . The result of mental work is scientific and spiritual values ​​or solutions that, through control actions on tools, are used to satisfy social or personal needs. Mental work appears in various forms, depending on the type of conceptual model and the goals that a person faces (these conditions determine the specifics of mental work).

Non-specific features of mental work include receiving and processing information, comparing the received information with that stored in a person’s memory, transforming it, identifying a problem situation, ways to resolve the problem, and forming the goal of mental work. Depending on the type and methods of converting information and developing solutions, reproductive and productive (creative) types of mental work are distinguished. In reproductive types of labor, previously known transformations with fixed action algorithms (for example, counting operations) are used; in creative work, the algorithms are either completely unknown or given in an unclear form.

A person’s assessment of himself as a subject of mental work, the motives of activity, the significance of the goal and the work process itself constitute the emotional component of mental work. Its effectiveness is determined by the level of knowledge and the ability to implement it, a person’s abilities and his volitional characteristics. With high intensity of mental work, especially if it is associated with a lack of time, phenomena of mental blockade (temporary inhibition of the process of mental work) may occur, which protect the functional systems of the central nervous system from dissociation.

One of the most important personality characteristics is intelligence. The condition for intellectual activity and its characteristics are mental abilities that are formed and developed throughout life. Intelligence is manifested in cognitive and creative activity, including the process of acquiring knowledge, experience and the ability to use it in practice.

Another, no less important side of personality is the emotional-volitional sphere, temperament and character. The ability to regulate personality formation is achieved through training, exercise and education. And systematic physical exercise, and even more so educational and training sessions in sports, have a positive effect on mental functions, forming mental and emotional resistance to strenuous activity from childhood. Numerous studies on the study of the parameters of thinking, memory, stability of attention, the dynamics of mental performance in the process of production activity in persons adapted (trained) to systematic physical activity and in non-adapted (untrained) individuals indicate that the parameters of mental performance directly depend on the level of general and special physical fitness . Mental activity will be less susceptible to the influence of unfavorable factors if you purposefully use the means and methods of physical culture (for example, physical training breaks, active rest, etc.) Matveev L.P. Theory and methodology of physical culture. - M.: FiS, 1991. - P. 33. .

The school day for most people is filled with significant mental and emotional stress. A forced working posture, when the muscles that hold the body in a certain state are tense for a long time, frequent violations of the work and rest regime, inadequate physical activity - all this can cause fatigue, which accumulates and turns into overwork. To prevent this from happening, it is necessary to replace one type of activity with another. The most effective form of rest during mental work is active rest in the form of moderate physical labor or physical exercise.

In the theory and methodology of physical education, methods of targeted influence on individual muscle groups and entire systems of the body are developed. The problem is presented by means of physical culture, which would directly influence the preservation of active activity of the human brain during intense mental work.

Physical exercise significantly affects changes in mental performance and sensorimotor skills in first-year students, and to a lesser extent in second- and third-year students. First-year students are more tired in the process of studying in conditions of adaptation to university education. Therefore, for them, physical education classes are one of the most important means of adapting to the conditions of life and study at a university. Physical education classes increase the mental performance of students of those faculties where theoretical classes predominate, and less of those whose curriculum alternates practical and theoretical classes. Physical education (course of lectures): Textbook / General. ed. L.M. Volkova, P.V. Polovnikova: St. Petersburg State Technical University, St. Petersburg, 1998.- P. 76. .

Students’ independent exercise in daily routine is also of great preventive importance. Daily morning exercises, a walk or jog in the fresh air have a beneficial effect on the body, increase muscle tone, improve blood circulation and gas exchange, and this has a positive effect on increasing the mental performance of students. Active recreation during the holidays is important: students, after relaxing in a sports and recreational camp, begin the school year with a higher performance capacity.

2. Means of physical culture that provide resistance to mental and physical performance

The main means of physical culture is physical exercise. There is a physiological classification of exercises, in which all the diverse muscle activities are combined into separate groups of exercises according to physiological characteristics.

The body's resistance to adverse factors depends on congenital and acquired properties. It is very mobile and amenable to training, both through muscular exercise and various external influences (temperature fluctuations, lack or excess of oxygen, carbon dioxide). It has been noted, for example, that physical training by improving physiological mechanisms increases resistance to overheating, hypothermia, hypoxia, and the effects of certain toxic substances, reduces morbidity and increases performance. Trained skiers, when their bodies are cooled to 35°C, maintain high performance. If untrained people are unable to perform work when their temperature rises to 37-38°C, then trained people successfully cope with the load even when their body temperature reaches 39°C or more Amosov N.M. Thoughts about health. - M.: FiS, 1987. - P. 90.

People who regularly and actively engage in physical exercise increase their mental, mental and emotional resilience when performing strenuous mental or physical activities.

The main physical (or motor) qualities that ensure a high level of human physical performance include strength, speed and endurance, which manifest themselves in certain proportions depending on the conditions for performing a particular motor activity, its nature, specificity, duration, power and intensity . To these physical qualities should be added flexibility and dexterity, which largely determine the success of certain types of physical exercises. The diversity and specificity of the effects of exercise on the human body can be understood by familiarizing yourself with the physiological classification of physical exercise (from the point of view of sports physiologists). It is based on certain physiological classification characteristics that are inherent in all types of muscle activity included in a specific group.

Thus, according to the nature of muscle contractions, muscle work can be static or dynamic in nature. Muscle activity while maintaining a stationary position of the body or its parts, as well as muscle exercise while holding a load without moving it, is characterized as static work (static effort). Static efforts are characterized by maintaining various body poses, and muscle efforts during dynamic work are associated with movements of the body or its parts in space. Physical culture of the student. Textbook for university students./ Under. ed. IN AND. Ilyinich. - M.: Gardariki, 1999. - P. 227. .

A significant group of physical exercises is performed under strictly constant (standard) conditions, both in training and in competitions; motor acts are performed in a certain sequence. Within the framework of a certain standardization of movements and the conditions for their implementation, the execution of specific movements is improved with the manifestation of strength, speed, endurance, and high coordination when performing them.

There is also a large group of physical exercises, the peculiarity of which is their non-standard, inconsistent conditions for their implementation, in a changing situation that requires an instant motor reaction (martial arts, sports games). Two large groups of physical exercises associated with standard or non-standard movements, in turn, are divided into exercises (movements) of a cyclic nature (walking, running, swimming, rowing, skating, skiing, cycling, etc.) and acyclic exercises nature (exercises without the obligatory continuous repetition of certain cycles that have a clearly defined beginning and end of the movement: jumping, throwing, gymnastic and acrobatic elements, lifting weights).

What cyclic movements have in common is that they all represent work of constant and variable power with varying durations. The diverse nature of the movements does not always make it possible to accurately determine the power of the work performed (i.e., the amount of work per unit of time associated with the strength of muscle contractions, their frequency and amplitude); in such cases, the term “intensity” is used. The maximum duration of work depends on its power, intensity and volume, and the nature of the work is associated with the process of fatigue in the body. If the power of work is high, then its duration is short due to the rapid onset of fatigue, and vice versa.

When working cyclically, sports physiologists distinguish a zone of maximum power (the duration of work does not exceed 20-30 s, and fatigue and decreased performance mostly occur within 10-15 s); submaximal (from 20-30 to 3-5 s); large (from 3-5 to 30-50 minutes) and moderate (duration 50 minutes or more) Nifontova L.N., Pavlova G.V. Physical education for people engaged in sedentary work. - M.: Soviet sport, 1993. - P. 85. .

The characteristics of functional changes in the body when performing various types of cyclic work in different power zones determine the sports result. For example, the main characteristic feature of work in the zone of maximum power is that muscle activity occurs in oxygen-free (anaerobic) conditions. The power of work is so great that the body is not able to ensure its completion through oxygen (aerobic) processes. If such power was achieved through oxygen reactions, then the circulatory and respiratory organs would have to ensure the delivery of more than 40 liters of oxygen per minute to the muscles. But even in a highly qualified athlete, with full strengthening of respiratory and circulatory function, oxygen consumption can only approach the indicated figure.

During the first 10-20 seconds of work, oxygen consumption in terms of 1 minute. reaches only 1-2 liters. Therefore, the work of maximum power is performed “in debt”, which is eliminated after the end of muscular activity. The processes of breathing and blood circulation during work of maximum power do not have time to intensify to a level that provides the required amount of oxygen to give energy to the working muscles. During sprinting, only a few shallow breaths are taken, and sometimes such running is performed while holding the breath completely.

At the same time, the afferent and efferent parts of the nervous system function with maximum tension, causing fairly rapid fatigue of the cells of the central nervous system. The reason for fatigue of the muscles themselves is associated with a significant accumulation of anaerobic metabolic products and depletion of energy substances in them. The main mass of energy released during maximum power operation is formed due to the energy of the breakdown of ATP and CP. The oxygen debt, eliminated during the recovery period after work performed, is used for oxidative resynthesis (reduction) of these substances. Human Anatomy. Textbook for physical education institutes. / Ed. IN AND. Kozlova. - M.: FiS, 1978. - P. 547. .

The decrease in power and increase in work duration is due to the fact that in addition to the anaerobic reactions of energy supply to muscle activity, the processes of aerobic energy formation also unfold. This increases (up to complete satisfaction of the need) the supply of oxygen to the working muscles. Thus, when performing work in a zone of relatively moderate power (long and ultra-long distance running), the level of oxygen consumption can reach approximately 85% of the maximum possible. In this case, part of the oxygen consumed is used for the oxidative resynthesis of ATP, CP and carbohydrates.

With prolonged (sometimes many hours) work of moderate power, the body's carbohydrate reserves (glycogen) are significantly reduced, which leads to a decrease in blood glucose, negatively affecting the activity of nerve centers, muscles and other working organs. To replenish the body's carbohydrate reserves during long runs and swims, special nutrition is provided with solutions of sugar, glucose, and juices.

Acyclic movements do not have a continuous repeatability of cycles and are stereotypically the following phases of movements with a clear completion. To perform them, it is necessary to show strength, speed, and high coordination of movements (movements of a power and speed-power nature). The success of performing these exercises is associated with the manifestation of either maximum strength, or speed, or a combination of both, and depends on the required level of functional readiness of the body systems as a whole. Human Anatomy. Textbook for physical education institutes. / Ed. IN AND. Kozlova. - M.: FiS, 1978. - P. 584. .

The means of physical culture include not only physical exercise, but also the healing forces of nature (sun, air and water), hygienic factors (work, sleep, nutrition, sanitary and hygienic conditions). The use of the healing powers of nature helps to strengthen and activate the body's defenses, stimulates metabolism and the activity of physiological systems and individual organs. To increase the level of physical and mental performance, you need to be in the fresh air, give up bad habits, exercise physical activity, and do hardening. Systematic physical exercises in conditions of intense educational activity relieve neuropsychic stress, and systematic muscular activity increases the mental, mental and emotional stability of the body during intense educational work.

3. Fatigue during physical and mental work. Recovery

Any muscular activity, physical exercise, or sports increase the activity of metabolic processes, train and maintain at a high level the mechanisms that carry out metabolism and energy in the body, which has a positive effect on a person’s mental and physical performance. However, with an increase in physical or mental stress, the amount of information, as well as the intensification of many types of activity, a special condition called fatigue develops in the body.

Fatigue is “a functional state that temporarily arises under the influence of prolonged and intense work and leads to a decrease in its effectiveness” Vilensky M.Ya., Ilyinich V.I. Physical culture of knowledge workers. - M.:3science, 1987. - P. 28. . Fatigue manifests itself in the fact that muscle strength and endurance decreases, coordination of movements worsens, energy costs increase when performing work of the same nature, the speed of information processing slows down, memory deteriorates, and the process of concentrating and switching attention and mastering theoretical material becomes more difficult. Fatigue is associated with a feeling of tiredness, and at the same time it serves as a natural signal of possible exhaustion of the body and a safety biological mechanism that protects it from overexertion. Fatigue that occurs during exercise is also a stimulant, mobilizing both the reserves of the body, its organs and systems, and recovery processes.

Fatigue occurs during physical and mental activity. It can be acute, i.e. manifest itself in a short period of time, and chronic, i.e. be of a long-term nature (up to several months); general, i.e. characterizing changes in the functions of the body as a whole, and local, affecting any limited muscle group, organ, analyzer.

There are two phases of fatigue: compensated (when there is no obvious decrease in performance due to the fact that the body’s reserve capacities are activated) and uncompensated (when the body’s reserve capacities are exhausted and performance is clearly reduced). Systematic performance of work against the background of under-recovery, ill-conceived work organization, excessive neuropsychic and physical stress can lead to overwork, and consequently to overstrain of the nervous system, exacerbations of cardiovascular diseases, hypertension and peptic ulcers, and a decrease in the body’s protective properties. The physiological basis of all these phenomena is an imbalance of excitatory-inhibitory nervous processes. Mental fatigue is especially dangerous for a person’s mental health; it is associated with the ability of the central nervous system to work under overload for a long time, and this can ultimately lead to the development of extreme inhibition and disruption of the coherence of the interaction of autonomic functions Vilensky M.Ya., Ilyinich V.I. Physical culture of knowledge workers. - M.:3science, 1987. - P. 39. .

It is possible to eliminate fatigue by increasing the level of general and specialized training of the body, optimizing its physical, mental and emotional activity.

The prevention and removal of mental fatigue is facilitated by the mobilization of those aspects of mental activity and motor activity that are not associated with those that led to fatigue. It is necessary to actively rest, switch to other activities, and use an arsenal of recovery tools.

Recovery is “a process that occurs in the body after cessation of work and consists in a gradual transition of physiological and biochemical functions to the initial state” Nifontova L.N., Pavlova G.V. Physical education for people engaged in sedentary work. - M.: Soviet sport, 1993. - With. 105. . The time during which the physiological status is restored after performing a certain job is called the recovery period. It should be remembered that in the body, both during work and in pre-work and post-work rest, at all levels of its vital activity, interconnected processes of consumption and restoration of functional, structural and regulatory reserves continuously occur. During work, the processes of dissimilation prevail over assimilation, and the more, the greater the intensity of the work and the less readiness of the body to perform it.

During the recovery period, assimilation processes predominate, and the restoration of energy resources occurs in excess of the initial level (super-recovery, or super-compensation). This is of great importance for increasing the fitness of the body and its physiological systems, ensuring increased performance.

Schematically, the recovery process can be represented in the form of three complementary links: 1) elimination of changes and disturbances in neurohumoral regulation systems; 2) removal of decay products formed in the tissues and cells of the working organ from the places of their origin; 3) elimination of decay products from the internal environment of the body.

Throughout life, the functional state of the body changes periodically. Such periodic changes may occur at short intervals or over long periods. Periodic recovery is associated with biorhythms, which are determined by daily periodicity, time of year, age-related changes, gender characteristics, the influence of natural conditions, and the environment. Thus, changes in time zone, temperature conditions, and geomagnetic storms can reduce recovery activity and limit mental and physical performance.

There are early and late recovery phases. The early phase ends a few minutes after light work, after hard work - after a few hours; late recovery phases can last up to several days.

Fatigue is accompanied by a phase of reduced performance, and after some time it can be replaced by a phase of increased performance. The duration of these phases depends on the degree of training of the body, as well as on the work performed.

The functions of various body systems are not restored simultaneously. For example, after a long run, the external respiration function (frequency and depth) is the first to return to its original parameters; after a few hours, heart rate and blood pressure stabilize; indicators of sensorimotor reactions return to the original level after a day or more; In marathon runners, the basal metabolism is restored three days after the race.

A rational combination of stress and rest is necessary in order to maintain and develop the activity of recovery processes. Additional means of recovery can be factors of hygiene, nutrition, massage, biologically active substances (vitamins). The main criterion for the positive dynamics of recovery processes is readiness for repeated activity, and the most objective indicator of restoration of performance is the maximum volume of repeated work. Particular care must be taken into account the nuances of recovery processes when organizing physical exercises and planning training loads. It is advisable to perform repeated loads in the phase of increased performance. Too long rest intervals reduce the effectiveness of the training process. Thus, after a speed run of 60-80 m, the oxygen debt is eliminated within 5-8 minutes. The excitability of the central nervous system remains at a high level during this time. Therefore, an interval of 5-8 minutes will be optimal for repeating speed work. Nifontova L.N., Pavlova G.V. Physical education for people engaged in sedentary work. - M.: Soviet sport, 1993. - With. 120

To speed up the recovery process, active rest is used in sports practice, i.e. switching to another type of activity. The importance of active rest for restoring performance was first established by the Russian physiologist I.M. Sechenov (1829-1905). He showed, for example, that a tired limb recovers quickly not with passive rest, but with work with another limb.

Conclusion

In our age of the atom and cybernetics, mental labor is increasingly replacing physical labor or closely merging with it. But, as I tried to show, intense mental work requires very good physical preparation of a person.

“All my life,” wrote I.P. Pavlov, I loved and love mental work, and physical work, and, perhaps, even more than the second. And I especially felt satisfied when I contributed some good guess to the latter, i.e. "connected his head with his hands" Ilyinich V.I. Professional and applied physical training of university students M.: Higher School, 1978. - P. 199. .

The founder of the cause of physical education in Russia, the outstanding physician and teacher P.F. Lesgraf has repeatedly emphasized that the discrepancy between a weak body and developed mental activity - “body and spirit” will sooner or later have a negative impact on the general condition and health of a person. “Such a violation of harmony... he wrote, does not go unpunished - it inevitably entails the impotence of external manifestations: there may be thought and understanding, but there will not be the proper energy for consistent testing of ideas and persistent implementation and application of them in practice.”

Many people believe that special “brain gymnastics” helps maintain high mental performance. We are talking about the so-called headstand. This exercise, combined with rhythmic flexion and extension of the legs at the knee and hip joints, not only increases blood flow to brain cells, strengthens blood vessels, but also promotes the outflow of venous blood from the lower extremities and pelvic organs, i.e. is an important means of preventing varicose veins, hemorrhoids, and kidney stones.

List of used literature

1. Life safety: A textbook for secondary vocational students. textbook establishments /S.V. Belov, V.A. Devisilov, A.F. Kozyakov and others; Under general ed. S.V. Belova. - 5th ed., rev. and additional - M.: Higher. school, 2006. - 423 p.: ill.

2. Life safety: Textbook for universities / S.V. Belov, A.V. Ilnitskaya, A.F. Kozyakov, L.L. Morozova and others; Under the general editorship. S.V. Belova. - 5th ed., rev. and additional - M.: Higher School, 2005. - 606 p.

3. Great medical encyclopedia. Main ed. B.V. Petrovsky. Ed. 3rd. T. 1-30, M., "Soviet Encyclopedia", 1974.

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All labor processes are conditionally divided into 2 types:

1) predominantly physical work;

2) predominantly mental work.

This division is very relative, because there is no purely physical and purely mental work - we can only talk about the predominance of mental or physical work.

While performing physical work, a person is to one degree or another loaded with mental activity. According to physiologists A.S. Egorova and V.P. Zagradsky, when cleaning, washing floors and wiping dust, a person is loaded with mental activity by only 0.9%, when working on a machine - by 25%, when driving a car in sparsely populated areas - by 35%, and when typing on a typewriter - by 73 %.

Physiology of physical labor.

Physical activity refers to the amount and intensity of a person’s muscular work associated with work, household work, physical education, sports, etc.

The study of physical activity caused by professional activities, their impact on the functional state and performance of a person is necessary to develop a rational organization of the work and rest regime, to ensure the quantitative and qualitative adequacy of nutrition for people of various professions to increase human performance, efficiency and productivity.

The study of physical activity is important and necessary due to the fact that the development of sensory organs (analyzers) and neuropsychic, emotional stress depend on the motor activity of the body. Over the course of long evolution, muscle tension and emotional tension necessarily accompanied each other. For example, a danger signal (meeting a predator) evoked negative emotions of fear and the need for motor reactions to escape (run away, hide); meeting small animals (food sources) evoked positive emotions and the need to catch up and catch them.

Emotions significantly increase muscle activity. In a state of passion (anger, fear), a person can perform such muscular work that he would never be able to cope with under normal conditions.

Human physical activity consists of static and dynamic work:

1.Static work represents the activity of muscles in conditions of maintaining a stationary position of the body or its parts, as well as holding any load. The muscles contract in an isometric mode, i.e. without changing length, therefore there is no mechanical work in a strictly physical sense.

Static work is the main component of maintaining a person’s working shape and is carried out through titanic and tonic contractions of certain muscle groups. Maintaining any position requires different tension from the muscles.

The simplest pose is lying down; When lying on your back, only the extensors are tense. The least muscle tension occurs when lying on your side with your limbs slightly bent. When sitting, the extensors of the torso and neck are most tense. The standing pose requires tension in many muscles of the torso, neck, and legs.

The amount of static work is determined by the product of the force supported by the muscles and the time during which the tense state occurs. Typically, the greater the tension, the shorter the time during which it can be maintained.

During static work, metabolism increases, energy consumption increases, while energy is not converted into mechanical work, but is released in the form of heat. Energy consumption is proportional to the weight of the supported load and the duration of its support. Static work is more tiring than dynamic work, because... accompanied by a continuous and intense flow of impulses from muscle proprioceptors to the central nervous system.

2. Dynamic work is associated with the movement of the body or its parts in space, i.e. with movements. In this case, muscle activity occurs in an auxotonic mode, which combines both contraction and tension. During dynamic work, energy is spent both on maintaining a certain contraction in the muscles and on the mechanical effect of the work and is measured by the product of the mass of the load and the distance over which it moves. In the conditions of human production activity, it is impossible to calculate work in mechanical units, therefore, to estimate the amount of physical activity, they use the definition of energy expenditure. Energy consumption is proportional to the amount of muscle work.

Thus, the assessment of the severity of work is based on a study of the amount of energy expenditure, the reaction of the cardiovascular system and respiration, thermoregulation and other physiological indicators. At low physical exertion, the pulse rate is 76-100 beats per minute, at medium stress - 110-125, at high stress - more than 175 beats per minute. But an increase in heart rate can also be associated with neuropsychic stress that accompanies a person’s professional activity. Therefore, a more reliable criterion for assessing the severity of physical activity is the amount of energy expenditure, which well reflects the dynamic load.

This principle has become widespread internationally. Based on various physiological indicators and energy expenditure, 4 groups were identified - categories of severity of physical work: light, moderate, heavy and very heavy. According to sanitary and hygienic standards, it is proposed to consider work that requires energy consumption of up to 150 kcal/hour as light work, and the heavy category includes work that requires energy consumption of more than 250 kcal/hour. The physiological norm of physical activity for a person is 180 kcal/hour.

Motor skills are new forms of motor actions developed through the mechanism of conditioned reflexes as a result of systematic exercises. The formation of a motor skill is carried out in 3 stages:

Stage 1 - characterized by a generalized efferent reaction, i.e. All muscles are activated at the same time, so movements are awkward, imprecise, posture and facial expressions are constrained, breathing is delayed.

Stage 2 - accompanied by improved coordination and accuracy of movements; There is some stereotypicality in the movements.

Stage 3 - characterized by a high degree of coordination and automation of the motor act.

In the education and implementation of skills, thinking, motivation, and memory play an important role, which provide trigger information and afferent synthesis. At all stages of skill formation, strength, speed, agility and endurance play an important role. When performing a skill, afferent impulses are sent to the central nervous system from proprioceptors, vestibular, auditory and tactile analyzers, due to which, at all stages of skill development, the compliance of the program and its implementation is monitored.

A large number of muscles are involved in the implementation of most household, work and sports motor skills. Some of them directly implement local voluntary movement itself, while others support the necessary posture, fix joints, etc. Physical exercise causes profound changes in all organs and systems of the human body, with physiological, biochemical and morphological changes occurring.

Due to neurohumoral regulation, functional changes in the autonomic nervous system begin in the pre-working period, i.e. only in preparation for work or physical exercise, continue during the exercise (while the muscle load is being performed) and remain after the end of the work. Autonomic processes are activated by the mechanism of conditioned and unconditioned reflexes. Along with the motor stereotype, a vegetative dynamic stereotype is also formed, which ensures correspondence between the level of various physiological functions and the level of motor activity.

In connection with physical work, the concept of “physiological reserve of the body” is highlighted. Physiological reserve is understood as the ability of an organ or functional system to increase the intensity of its activity many times over compared to a state of relative rest. This ability has developed in the process of evolution and depends on physical training.

The physiological reserve is clearly visible in the example of increased blood circulation in the skeletal muscle during physical work. At rest, skeletal muscles consume 25-30% of IOC, during heavy physical work - 80-85%; MOQ increases from 5 to 30 liters; heart rate (in swimmers, for example) increases from 170 to 205 beats/min. Respiratory reserves are great: its activity during physical work increases 10 times, oxygen consumption increases 15-16 times.

However, in the process of performing his professional activity, a person does not work to the limit of his physical capabilities, because such work does not last long and leads to fatigue of the body. The volume of physiological reserve stands out most clearly in sports, where properly organized training expands the physiological reserve of the body, making it more resilient and resistant to negative influences. For example, Arshavsky’s work has shown that the performance of the neuromuscular system with normal blood circulation can be maintained for a long time (4-5 hours), if the rhythm of contractions is at such intervals that anabolic processes have time to be completely completed. Thus, a motor act that is correctly organized in time can be carried out without signs of fatigue. High performance during physical activity is associated with the use of the aerobic capabilities of the body and with the possibility of long-term maintenance of a stable state of respiratory functions, the cardiovascular system, i.e. transport systems throughout the entire labor process, capable of regulating homeostasis.

Systematic exercise improves the physiological reserve of the body, increases the mass of skeletal muscles, chest volume, vital capacity, and muscle strength. Physical labor and sports in their optimal form can act as a source of increasing the body’s reserve capabilities even in old age, pushing back the boundaries of aging, although the body’s physiological reserves decrease with age. Maximum muscle strength occurs between the ages of 20 and 30, and, on the contrary, with excessive, backbreaking nature of work, it can be the cause of early wear, aging, and withering of the body.

In a well-trained body, the physiological reserve is not used to the maximum, and the changes observed in the body during and outside of physical work are characterized by a certain economization of functions. Thus, the heart rate of well-trained athletes is 40-45 beats/min. at a high level of BSS - 100 ml, - the value of the basal metabolic rate is 20-40% lower than its proper values. This allows the body to use energy resources most efficiently during physical effort.

The economization of functions is based on the following restructuring of the functional systems of the body. Moderate hypertrophy of the heart occurs, the ratio of its mass to body weight can increase by 40%. This is accompanied by the development of a network of capillaries and anastomoses between them, an increase in the content of glycogen and myoglobin in the heart muscle. During the training process, the diastole period significantly lengthens, during which the resynthesis of energy-rich phosphorus compounds occurs in the myocardium. In addition, mitochondria swell and their energy-producing surface increases.

Systematic exercises lead to improvement of the respiratory muscles. The excitability of the respiratory center in a trained person is somewhat reduced, so they are able to hold their breath for a longer time. Athletes are also characterized by a high level of utilization of oxygen by tissues (from 30% increases to 70%), nutrients, and removal of decay products.

In increasing the body's performance, an important role is played by the endocrine glands: hormones of the adrenal cortex, pancreas (insulin), which provide a high level of carbohydrate metabolism, which underlies high performance. Metabolism is also activated by the thyroid gland, adrenal glands, and pituitary gland. High fitness of the body is achieved only with sufficient volitional and psychological preparation.

Physiology of mental work .

For modern practical medicine, the study of the problem of human mental and emotional activity is of great importance. We have already said that work is not limited to physical and mental activity; it is almost always associated with emotional experiences.

The phylogeny of the central nervous system shows that its structure and activity are becoming more complex all the time. At the same time, if previously the brain of most people controlled mainly physical activity, then over the last hundred years, and especially the last decades, the volume of human intellectual activity in all spheres of production has increased enormously. The working conditions of modern man have changed dramatically. Modern man has found himself at a stage of social development that is characterized by a large volume of varied information. The central nervous system experiences a heavy load, and the demands placed on human intellectual activity increase enormously.

In addition to professional characteristics, another important aspect of life that increases the load on the central nervous system is its saturation with a variety of information. This, for example, is an increase in population, especially in cities, an increase in the speed of various types of transport, television, radio, telephone, vast literature, art, and, finally, an increase in the rhythm of life in general and the complication of relationships between people. All these phenomena, characteristic of our “nervous” age, create additional stress for the intellectual and emotional spheres.

In the sphere of human emotions and mental activity, there is a significant intensification. All this leads to the fact that the modern worker does not have time to adequately and quickly respond to all biologically and semantically significant information. More and more unreacted and unrealized emotions and tasks of various nature accumulate. In this regard, the tension of the regulatory mechanisms of the central nervous system and the homeostatic constants of the body increases significantly.

To think that it is possible to stop scientific and technological progress, scientific and technological progress and the associated increase in nervous overload is naive and unrealistic. There is only one way left - to train the brain, facilitate the perception and processing of various information, and create the necessary optimum activity of the whole organism.

It should be noted that under the influence of chronic exposure to a complex of emotional stimuli, overstrain of the nervous system in mental workers and students can take on a stagnant character and thereby lead to the emergence of neuroses.

Never before during its existence has humanity been in such dire need of solving such problems of the century as mental fatigue, neuro-emotional stress and neurotic disorders.

Emotional stress and nervous tension are not the same thing. Nervous tension is not always accompanied by negative emotions. In this regard, it is very important, firstly, to accurately identify the presence of an emotional sign in a person in each case, because positive emotions in most cases are not harmful and do not interfere with human activity, and, secondly, to know that only the chronic impact of emotional stress on the body is significant in the occurrence of nervous strain, fatigue and neurotic conditions. Constant or repeated emotional stress disrupts the coordinated work of the body's homeostatic constants and increases the excitability of various nervous formations. In the same aspect, the possibility of the occurrence of nervous overstrain of an information nature and information neuroses is considered - in individuals who almost constantly process a large flow of emotionally charged information under conditions of time shortage (student before an exam).

Features of mental and emotional activity of students and

teachers.

In conditions of rapid growth of scientific information, the training of specialists with higher education becomes more complicated every year. Increasingly high demands are placed on them, both in terms of intellectual abilities and physical development.

Students differ from other categories of knowledge workers in that their mental activity is determined by the learning process and is associated with the accumulation of knowledge and the development of intellectual abilities. It is very important to physiologically substantiate and rationalize the study load in order to prevent overstrain or disruption of brain adaptation mechanisms, which in students are still in the stage of development and improvement.

Yesterday's schoolchild, becoming a student, finds himself in new conditions of activity with an intensive academic load, high social activity and new life situations. One of the characteristic features of students is the fact that passing final exams at school and preparing for entering college occur in a short period and very intensively. This plays a significant role in the development of adaptive and compensatory mechanisms of future students’ GNI.

During this same difficult period, the elements of social adaptation of the individual change, a transition is made from childhood dependence to independent activity, the activity of an adult with all his rights and responsibilities. In this regard, significant difficulties, especially for nonresident students, are: distance from their family and a feeling of loneliness, inclusion in a new team, new living conditions, etc. Upon entering college, young people find themselves in new educational conditions compared to the average school (an increase in the number of teachers, unusual teaching methods, high pedagogical requirements, the need to independently plan study time and other issues of student life, a different examination system, etc.) Consequently, there is a violation of the school stereotype and the formation of a new, more complex university stereotype of behavior.

A particularly important place in the learning process is occupied by the information overload of students with numerous academic subjects, the quality and scientific level of which is constantly increasing. In addition, situations of emotional stress, which arise especially during exams, traumatize and sensitize the very labile and still poorly controlled emotional sphere of students.

The workload and intensity of students' work is determined by the conditions of the educational process. According to academic standards, the workload of students at all universities, as a rule, should not exceed 36 hours per week. However, during study, the working week is often 40-43 hours. At the same time, there is an uneven distribution of the teaching load and a violation of the work schedule. Calculations show that the working day of 1st-3rd year students averages 10-12 hours. A survey of junior year students at many universities showed that they sleep no more than 7 hours a day and spend 3 hours daily on independent work. They often do homework in the evenings and on Sundays. (Naturally, we are talking about conscientious students).

Modern complex learning tasks that higher education is called upon to solve place increased demands on teachers. Teachers make up a very significant portion of knowledge workers. Along with high scientific and pedagogical qualifications and good knowledge of the subject, the teacher is required to have high erudition and intelligence, good upbringing, mastery of oratory and artistic skills, neatness, exceptional composure and concentration, kindness and strict discipline. The clinical teacher is also distinguished by his high professional skill in healing.

The most difficult type of work is lecturing, which is accompanied by neuropsychic stress and requires sustained attention, subtle and precise interaction of analytical systems and all higher mental functions: thinking, will, memory, perception, attention, imagination, etc. Lecture work, as a rule, is combined with extensive teaching and educational work, research activities and, most importantly, the formation of the ability to control an audience.

The labor activity of higher education teaching staff can be considered as highly qualified mental work, which is accompanied by nervous-emotional stress and frequent emotional manifestations.

A specific feature of students’ activities can be considered that they do not know how to work. The great potential capabilities of their body are used unpurposefully and irrationally, without the necessary skills. In this regard, a significant study load for students, especially 1st year students, is a significant factor, which causes them neuropsychic stress and a state of frustration during the exam period.

The working day of university teachers, as is known, should be 6 hours. However, their working day often reaches 8-10 hours. At the same time, lecturing and teaching work takes up the most time. In addition to lecture work, teachers conduct scientific research, and clinicians conduct medical work. Specific features of highly qualified teaching work are constant communication with students, as well as careful preparation before each lecture. In addition, if an exam almost always causes emotional stress for a student, then it requires a lot of mental stress from the teacher, intellectual capabilities and the manifestation of professional experience.

Physiological differences between mental and physical labor.

Mental and physical labor are interconnected and influence each other. Mosso (1893) used an ergograph to determine that a professor who gave a lecture to students becomes so tired that after the lecture the muscle strength of his arm decreases by 20%. After a 3-hour exam, a student’s muscle strength drops by 4 times. In turn, under the influence of physical fatigue, the productivity of intellectual activity decreases. At the same time, there are a number of significant features that distinguish mental labor from physical labor.

First of all, it should be noted that overcoming the significant differences between mental and physical labor does not mean eliminating their relative independence. This independence is apparently determined by the specifics of their physiological mechanisms. In addition, even if we say that there is no “pure” mental labor without physical elements, and, conversely, physical labor without mental elements, this should not mean that there is no difference between mental and physical labor.

Kandror (1970) notes that with any type of labor there is a need to separately evaluate the energy and information aspects of the labor process. In his opinion, it is advisable to characterize the first by the degree of severity, and the second by the degree of tension. It is the energy and information aspects of labor activity that primarily distinguish physical labor from mental labor.

Researchers in the physiology of work know well how effective and long-term physical work is ensured, but they still have little knowledge of what means and resources are used to ensure mental work, not to mention the complex structural and functional organization of the brain, which ensures mental activity.

It is known that during physical work there is an intensification and deepening of breathing, a redistribution and increase in the amount of circulating blood, an intensification and increase in heart rate, an increase in the level of sugar and formed elements in the blood. Mental activity, colored by emotions, causes almost the same changes. However, if these peripheral shifts in autonomic reactions are necessary to provide energy to working muscles, or more precisely, to cover energy costs during physical work, then these same shifts that occur during mental, emotionally intense work are far from necessary, because During mental activity, there is no large energy consumption and, accordingly, utilization, i.e. implementation of excess exchange.

Consequently, these vegetative-humoral changes during mental work do not have the same direct purpose as during physical work. Any mental work, no matter how complex it may be, does not require a significant increase in sugar levels, the number of leukocytes, steroid hormones, etc. for its implementation. Hyperfunction of the autonomic organs during emotional work occurs not due to muscle tension and increased oxygen and energy demand from the periphery, but due to the activation of brain structures, especially subcortical, limbic-reticular and thalamo-hypothalamic formations under the influence of mental-emotional work.

Autonomic and humoral shifts during mental work or pre-launch states are conditioned reflex in nature, occur with the participation of emotional accompaniment and are not associated with activation of the motor system.

There is no doubt that mental work involves a greater number of nervous elements than physical work. Based on modern data from neurophysiology and neuropsychology, it must be assumed that mental work is the result of the most complex combinations of nervous processes and histochemical changes in millions of neurons of the cortical-subcortical formations. Mental work differs from physical work, apparently also in that the systemic functioning of the brain during mental activity is not only more complex and highly qualified, but also more extensive and includes a larger number of systems and subsystems than during physical work. There is also more load on the analyzers.

The difference between physical and mental labor is also evident in relation to a number of other indicators. Changes in physiological functions under the influence of physical work are more pronounced than in the case of mental work. Muscular fatigue also has a more or less clear picture, which makes it different from mental fatigue. The first, unlike the second, can be quantitatively measured. When muscle fatigue sets in, the work being done almost completely stops, which is not the case with mental fatigue.

Mental activity can be carried out for a long time; it does not stop after finishing a specific job. If we can stop muscular work voluntarily, then in relation to mental work, especially emotionally charged, it is difficult to do this. Physiological changes that occur during mental labor are eliminated much more slowly than during physical labor, which can be considered as an aftereffect phenomenon. If at the end of mental activity only traces of excitation or inhibition are often observed, then after physical labor late muscle pain is usually characteristic. The feeling of fatigue is also more severe after physical activity. After it, deep sleep comes faster. The result of physical labor is tangible and visible, but the result of intellectual labor is sometimes not obtained immediately, and some additional actions are necessary to express it (speech, writing, drawing, etc.).

It is assumed and proven by a number of scientific works that labor created man. The concept of “labor” includes its various types. Meanwhile, there are two main types of human labor activity - physical and mental labor and their intermediate combinations.

Physical work - this is a type of human activity, the characteristics of which are determined by a complex of factors that distinguish one type of activity from another, associated with the presence of any climatic, industrial, physical, information and similar factors. Performing physical work is always associated with a certain severity of labor, which is determined by the degree of involvement of skeletal muscles in the work and reflects the physiological cost of primarily physical activity.

According to the degree of severity, work is classified into physically light, moderate, hard and very hard work.

Criteria for assessing the severity of work are ergometric indicators (amount of external work, moved loads, etc.) and physiological (levels of energy consumption, heart rate, other functional changes).

Brainwork - this is a person’s activity to transform the conceptual model of reality formed in his mind by creating new concepts, judgments, conclusions, and on their basis - hypotheses and theories. The result of mental work is scientific and spiritual values ​​or solutions that, through control actions on tools, are used to satisfy social or personal needs. Mental work appears in various forms, depending on the type of conceptual model and the goals that a person faces (these conditions determine the specifics of mental work). Non-specific features of mental work include receiving and processing information, comparing the received information with that stored in a person’s memory, transforming it, identifying a problem situation, ways to resolve the problem, and forming the goal of mental work. Depending on the type and methods of converting information and developing solutions, reproductive and productive (creative) types of mental work are distinguished. In reproductive types of labor, previously known transformations with fixed action algorithms (for example, counting operations) are used; in creative work, the algorithms are either completely unknown or given in an unclear form.

Brainwork

Sufficiently objective criteria have not been developed to characterize the intensity of mental work from a physiological point of view. It can be characterized by the volume of information to be memorized and (or) analyzed, as well as the speed of receipt of information and decision-making, the degree of responsibility for possible errors in decision-making, etc. This is typical for such professions as dispatchers, operators of central control panels of complex objects, leaders of labor collectives.

The essence of mental work is studied and characterized in various aspects: - physiologists and psychologists consider mental work as processes of higher nervous activity that realize the functions and relationships of the brain with receptors and effectors; - psychologists and sociologists study the motives of mental activity, its structure, logic, as well as the behavior of workers, the moral and psychological climate; - cybernetics specialists consider mental work as a model of an information processing system.

Mental work covers a very wide range of activities that are different in nature and content. These include: - scientific work - the work of scientists engaged in research work; - engineering work - the work of engineering and technical workers engaged in design, engineering and technological work; - pedagogical work - the work of professors, teachers and teachers; - medical work; - managerial work - the work of managers and specialists who manage labor collectives; - production labor - the labor of workers and specialists managing complex technological processes, equipment, automated and robotic systems; - auxiliary labor - the work of employees conducting accounting, etc.

The subject of mental work (regardless of the type) is information containing the state of practice and tasks for changing it.

Mental work consists of processing and analyzing a large amount of varied information, and as a consequence of this, the mobilization of memory and attention, and muscle loads are usually insignificant. This work is characterized by a significant decrease in motor activity (hypokinesia), which can lead to cardiovascular pathology; prolonged mental stress depresses the psyche, impairs the functions of attention and memory. The main indicator of mental work is tension, which reflects the load on the central nervous system.

The intensity of any labor is characterized by the amount of productive consumption of labor per unit of time. Labor costs in a physiological sense are the expenditure of a person’s functional capabilities, leading to a decrease in performance and the appearance of fatigue. Psychophysiological limiters during mental work are: - indicator of decreased performance; - an indicator of the reliability of human functioning in various systems; - magnitude and symptoms of subjectively felt fatigue; - indicators of mental and emotional state.

One of the most important indicators of employee performance in the “man-machine” system, as well as when performing the duties of a dispatcher, operator and other similar professions, is attention.

Physical work

As for physical labor, quite objective criteria for assessing severity have been defined for it - these are energy consumption.

All types of physical work are performed with the participation of muscles, which, when contracting, perform work in the physiological sense of the word. Replenishment of muscle energy occurs due to the consumption of nutrients that are constantly supplied to the bloodstream. The same blood flow carries away waste substances from the muscles - oxidation products. The main source of energy is the oxidation of glycogen by oxygen, also contained in the blood. Glycogen is a polysaccharide formed by glucose residues. It is deposited in the cytoplasm of liver and muscle cells. When there is a lack of glucose in the body, glycogen is broken down by enzymes (reaction accelerators) into glucose, which enters the blood.

Physical work is usually divided into three groups according to its severity. This division is based on oxygen consumption as one of the objective indicators of energy consumption available for measuring. In this regard, work is distinguished: light, medium and heavy.

TO light include work performed while sitting, standing or associated with walking, but without systematic stress, without lifting and carrying heavy objects. These are works in clothing production, precision instrument making and mechanical engineering, printing, communications, etc.

Go to category moderate severity include work associated with constant walking and carrying small (up to 10 kg) weights, and performed while standing. This is work in mechanical assembly shops, mechanized open-hearth, rolling, foundry, forging, thermal shops, etc.

Go to category heavy include work associated with systematic physical stress, as well as with constant movement and carrying of significant (more than 10 kg) weights. These are blacksmith works with hand forging, foundry works with manual filling and pouring of flasks, etc.

So, the main physiological reactions of the body to physical work are increased heart rate, increased blood pressure, increased breathing and increased pulmonary ventilation, changes in blood composition, and increased sweating. Changes gradually increase, reaching a certain level at which the increased work of organs and systems is balanced with the needs of the body.

After cessation of work, a recovery period begins when the altered functions gradually return to normal. But the duration of restoration of various functions is not the same: - pulse, pressure, respiratory rate and pulmonary ventilation are restored in 10-15 minutes; - blood composition, etc. – in 45-50 minutes.

This is due to the fact that during intense work the body’s internal resources are mobilized, non-working tissues and organs are depleted of oxygen and nutrients, as well as the reserves of the muscle cells themselves are absorbed, which, due to these internal reserves, can work for some time without consuming oxygen (the so-called anaerobic phase of muscle work). To replenish these reserves during rest, the body continues to consume increased amounts of oxygen.

If, during prolonged hard work and when all the body's resources are mobilized, the delivery of the required amount of oxygen and nutrients is not ensured, muscle fatigue occurs.

Muscles work not only when a person moves weights, but also when he holds them in place, or holds the weight of his own body or its individual parts (torso, arms, head). In this regard, the main indicators of the severity of the labor process are: - physical dynamic load; - the mass of the load lifted and moved manually; - stereotypical labor movements; - static load; - working posture; - body tilts, movement in space.

A forced and even more uncomfortable body position, even in the case of light work, can lead to rapid fatigue, because static load on the same muscle groups is more tiring. The working posture can be free, uncomfortable, fixed or forced. Free poses include comfortable sitting postures, with the possibility of changing the working position of the body or its parts. Fixed working posture is the impossibility of changing the relative position of various parts of the body relative to each other. Similar postures are encountered when performing work related to the need to distinguish small objects during work. The most rigidly fixed working postures are for representatives of those professions who have to perform their main production operations using optical magnifying devices - magnifiers and microscopes. Uncomfortable working postures include postures with a large bend or turn of the torso, with arms raised above shoulder level, and with inconvenient placement of the lower extremities. Forced postures include working postures lying down, kneeling, squatting, etc.

Fatigue and recovery during physical and mental work (definition, symptoms of fatigue, types of fatigue, phases of fatigue, what recovery depends on, scheme of the recovery process, recovery criteria).

Fatigue is a functional state that temporarily arises under the influence of prolonged and intense work and leads to a decrease in its effectiveness.

Fatigue manifests itself in the fact that muscle strength and endurance decreases, coordination of movements worsens, energy costs increase when performing work of the same nature, the speed of information processing slows down, memory deteriorates, and the process of concentrating and switching attention and mastering theoretical material becomes more difficult.

Fatigue is associated with a feeling of tiredness, and at the same time it serves as a natural signal of possible exhaustion of the body and a safety biological mechanism that protects it from overexertion. Fatigue that occurs during exercise is also a stimulant, mobilizing both the reserves of the body, its organs and systems, and recovery processes.

Fatigue occurs during physical and mental activity. It can be acute, i.e. manifest itself in a short period of time, and chronic, i.e. be of a long-term nature (up to several months); general, i.e. characterizing changes in the functions of the body as a whole, and local, affecting any limited muscle group, organ, analyzer.

There are two phases of fatigue:

· compensated (when there is no obvious decrease in performance due to the fact that the body’s reserve capabilities are activated);

· uncompensated (when the body’s reserve capacities are exhausted and performance is clearly reduced).

Systematic performance of work against the background of under-recovery, ill-conceived work organization, excessive mental and physical stress can lead to overwork, and therefore to overvoltage nervous system, exacerbations of cardiovascular diseases, hypertension and peptic ulcers, decreased protective properties of the body.

It is possible to eliminate fatigue by increasing the level of general and specialized training of the body, optimizing its physical, mental and emotional activity.

The prevention and removal of mental fatigue is facilitated by the mobilization of those aspects of mental activity and motor activity that are associated with those that led to fatigue. It is necessary to actively rest, switch to other activities, and use an arsenal of recovery tools.

Recovery- a process occurring in the body after cessation of work and consisting in a gradual transition of physiological and biochemical functions to the original state.

The time during which the physiological status is restored after performing a certain job is called recovery period.

It should be remembered that in the body, both during work and in pre-work and post-work rest, at all levels of its vital activity, interconnected processes of consumption and restoration of functional, structural and regulatory reserves continuously occur. During work, the processes of dissimilation prevail over assimilation, and the more, the greater the intensity of the work and the less readiness of the body to perform it. During the recovery period, assimilation processes predominate, and the restoration of energy resources occurs in excess of the initial level (over-recovery, or super-compensation)(illustration). This is of great importance for increasing the fitness of the body and its physiological systems, ensuring increased performance.

Distinguish early and late recovery phase. The early phase ends a few minutes after light work, after heavy work - after a few hours. Late recovery phases can last up to several days.

Fatigue is accompanied by a phase of decreased performance, and after some time it can be replaced by a phase of increased performance. The duration of these phases depends on the degree of training of the body, as well as on the work performed.

A rational combination of stress and rest is necessary in order to maintain and develop the activity of recovery processes. Additional recovery tools There may be factors of hygiene, nutrition, massage, biologically active substances (vitamins).

The main criterion for the positive dynamics of recovery processes is readiness for repeated activity, and the most objective indicator of restoration of performance is the maximum volume of repeated work.

Particular care must be taken into account the nuances of recovery processes when organizing physical exercises and planning training loads.

It is advisable to perform repeated loads in the phase of increased performance. Too long rest intervals reduce the effectiveness of the training process.

To speed up the recovery process, active rest is used in sports practice, i.e. switching to another type of activity.

11. Indicators of fitness of the human body (list and characterize, give examples).

Fitness of the human body is the ability to perform heavy physical activity, usually observed in people whose lifestyle or profession is associated with intense muscle activity. A trained body, adapted to physical activity, is able not only to carry out intense muscular work, but also turns out to be more resistant to situations that cause illness, to emotional stress, and environmental influences.

Thus, indicators of fitness at rest include:
1) changes in the state of the central nervous system, increased mobility of nervous processes, shortening of the latent period of motor reactions;
2) changes in the musculoskeletal system;
3) changes in the function of the respiratory organs, blood circulation, blood composition, etc.

that trained individuals relax their muscles better than untrained individuals. Additional muscle tension is always associated with additional energy costs. In addition, trained people have a slightly lower excitability of the nervous system at rest compared to untrained people. Along with this, they have a good balance between the processes of excitation and inhibition. All these changes indicate that a trained body spends energy very economically at rest; in the process of deep rest, a restructuring of its functions takes place, and energy is accumulated for the upcoming intense activity.

Reactions to standard (testing) loads trained individuals are characterized by the following features: 1) all indicators of the activity of functional systems at the beginning of work (during the period of development) are higher than those of untrained individuals; 2) during work, the level of physiological changes is less high; 3) the recovery period is significantly shorter.
Two conclusions can be drawn regarding the impact of training. The first is that a trained body performs standard work more economically than untrained. Training causes such adaptive changes in the body that cause economization of all physiological functions. The body's violent reaction to work in an untrained person is manifested in wasteful expenditure of strength and energy, excessive functioning of various physiological systems, and their poor mutual regulation. In the process of training, the body acquires the ability to react to the same work more moderately, its physiological systems begin to act more consistently and coordinatedly, and energy is spent more economically. The second conclusion is that the same work becomes less tiring as training develops. For an untrained person, standard work may be relatively difficult, performed with the tension characteristic of heavy work, and causes fatigue, while for a trained person the same load will be relatively easy, require less stress and will not cause much fatigue.

Thus, the body of a person who is systematically engaged in active motor activity is able to perform work that is more significant in volume and intensity than the body of a person who is not engaged in it. This is due to the systematic activation of the physiological and functional systems of the body, the involvement and increase of their reserve capabilities, a kind of training in the processes of their use and replenishment.