One of them was noticed by Academician V.P. Skulachev, who discovered a new, previously unknown pathway of La oxidation. During heavy physical work, when the energy demand exceeds the energy-converting capacities of the cell, the energy homeostasis is disturbed and the ATP content decreases. The latter negatively affects the work of all ATP-dependent enzymes, first of all Na+, K+, ATPase. As a result, Na+ concentration in cytoplasm increases, which leads to swelling of cell membranes. Under these conditions, part of cytochrome c dissociates from the surface of mitochondrial membranes and appears in the intermembrane space.

Cytochrome C provides extramitochondrial oxidation of lactate using cytosolic NADH according to the scheme:

"lactate -" NADN -" flavoprotein -" C extramitochondrial -" C mitochondrial -" aa3 -" O2

In this case, part of the redox chain is realized in the extramitochondrial space, bypassing complexes I and III, and the final stage of oxidation takes place with the participation of complex IV. This reaction scheme avoids the accumulation of excess La in muscle.

Disruption of ATP resynthesis can occur when intramuscular energy sources are depleted or when a decrease in the efficiency of the blood supply to the muscles leads to a decrease in the delivery of energy substrates and oxygen to them.

The body responds by changing the metabolic response to strenuous exercise following an endurance training program as follows:

Respiratory metabolic rate and muscle respiratory rate decrease;

concentration of free fatty acids in plasma increases;

increased intramuscular triglyceride utilization;

muscle glycogen utilization rate decreases;

blood glucose consumption by muscles decreases;

lipid oxidation becomes higher compared to carbohydrates;

accumulation in La muscle is insignificant.

The systematic performance of endurance exercise induces muscular and cardiovascular adaptation, which determines the ways of providing energy and oxygen. This adaptation, which includes both ultrastructural and metabolic changes, leads to improved oxygen delivery and extraction by contracting muscles and modifies and improves the regulation of metabolism in individual muscle fibers.

Muscle adaptation to training aimed predominantly at endurance development predetermines the development of the following qualities:

Selective hypertrophy of type I fibers;

increase in the number of capillaries per fiber;

increase in myoglobin content;

increased ability of mitochondria for ATP oxidative resynthesis;

increase in the size and number of mitochondria;

increase in the ability to oxidize lipids and carbohydrates;

increased use of lipids for energetic purposes;

increased glycogen and triglyceride content.

Development of physical qualities

Endurance

In cyclical sports, endurance (as a physical quality) is one of the components that ensure high athletic performance. Usually, endurance is understood as the ability to work without fatigue and to resist the fatigue that occurs during the performance of the work.

Endurance is manifested in two main forms:

In the duration of work at a given level of power before the first signs of pronounced fatigue appear;

The rate of the decrease of work capacity at the onset of fatigue.

As a multifunctional property of the human body, endurance integrates a large number of diverse processes occurring at different levels, from the cellular to the whole organism. The leading role in the manifestation of endurance belongs to the factors of energy metabolism.

According to the three different metabolic sources of energy in a human being, there are three endurance components: aerobic, glycolytic and alactate, each of which can be characterized by power, capacity and efficiency indices.

The power index assesses the maximum amount of energy per unit time that can be supplied by each of the metabolic processes.

The capacity index assesses the total stores of energy substances in the body or the total amount of work accomplished from a given source.

Efficiency criteria show how much external mechanical work can be accomplished for each unit of energy released.

During any physical exercise lasting more than a few minutes, the main pathway for ATP resynthesis is oxidative phosphorylation in the mitochondria, which use carbohydrates and lipids as energy substrates.

This process requires an adequate supply of oxygen delivered by the blood and an adequate amount of energy sources. The latter can be extracted from stores located in the muscle fibers themselves (glycogen, triglycerides, phosphagens) as well as from circulating blood (glucose and free fatty acids).

The problems of converting chemical energy into mechanical energy gave rise to the phenomenon not only of sprinters, but also of stayers. The latter have to perform grueling work for long periods of time. Of course, under these conditions, the system of aerobic oxidation of the substrate is fully operational. However, the amount of oxygen consumed by the muscles is limited. The presence of the oxygen limit determines the need to use additional anaerobic processes, leading to the inevitable accumulation of La in the muscles. Scientists had long been unable to unravel the phenomenon of steppers, until they discovered two remarkable features of skeletal muscle performance.

One of them was noticed by Academician V.P. Skulachev, who discovered a new, previously unknown pathway of La oxidation. During heavy physical work, when the energy demand exceeds the energy-converting capacities of the cell, the energy homeostasis is disturbed and the ATP content decreases. The latter negatively affects the work of all ATP-dependent enzymes, first of all Na+, K+, ATPase. As a result, Na+ concentration in cytoplasm increases, which leads to swelling of cell membranes. Under these conditions, part of cytochrome c dissociates from the surface of mitochondrial membranes and appears in the intermembrane space.

Cytochrome C provides extramitochondrial oxidation of lactate using cytosolic NADH according to the scheme:

"lactate -" NADN -" flavoprotein -" C extramitochondrial -" C mitochondrial -" aa3 -" O2

In this case, part of the redox chain is realized in the extramitochondrial space, bypassing complexes I and III, and the final stage of oxidation takes place with the participation of complex IV. This reaction scheme avoids the accumulation of excess La in muscle.

Disruption of ATP resynthesis can occur when intramuscular energy sources are depleted or when a decrease in the efficiency of the blood supply to the muscles leads to a decrease in the delivery of energy substrates and oxygen to them.

The body responds by changing the metabolic response to strenuous exercise following an endurance training program as follows:

Respiratory metabolic rate and muscle respiratory rate decrease;

concentration of free fatty acids in plasma increases;

increased intramuscular triglyceride utilization;

muscle glycogen utilization rate decreases;

blood glucose consumption by muscles decreases;

lipid oxidation becomes higher compared to carbohydrates;

accumulation in La muscle is insignificant.

The systematic performance of endurance exercise induces muscular and cardiovascular adaptation, which determines the ways of providing energy and oxygen. This adaptation, which includes both ultrastructural and metabolic changes, leads to improved oxygen delivery and extraction by contracting muscles, and modifies and improves the regulation of metabolism in individual muscle fibers.

Muscular adaptation to training aimed at the predominant development of endurance predetermines the development of the following qualities:

selective hypertrophy of type I fibers;

increase in the number of capillaries per fiber;

increase in myoglobin content;

increased ability of mitochondria for ATP oxidative resynthesis;

increase in the size and number of mitochondria;

increase in the ability to oxidize lipids and carbohydrates;

increased use of lipids for energetic purposes;

increased glycogen and triglyceride content.

Trained muscles show a higher capacity for carbohydrate oxidation. Consequently, more pyruvate can be reduced and passed through the Krebs cycle. This also increases the ability of exercised muscles to utilize lipids. This is due to an increase in the activity of lipolytic enzymes and an increase in capillary density in the muscle, allowing more free fatty acids to be captured from the blood. The activity of enzymes in the capillary endothelium of trained muscles increases, as does the ability of mitochondria to oxidize free fatty acids. However, the most important effect of enzymatic changes occurring in muscles under the influence of training aimed at the preferential development of endurance is to increase the contribution of lipids and consequently decrease the contribution of carbohydrates in oxidative energy metabolism (ATP resynthesis) when performing sub-maximal aerobic power exercise.

Under the influence of training during exercise, both the respiratory exchange coefficient and the local respiratory coefficient directly in the working muscles decrease. The increase in lipid oxidation is obviously a consequence of the increased substrate oxidation capacity compared with the glycolytic capacity, which shows a less pronounced response during endurance training.

Endurance athletes use more fat and less carbohydrates not only when performing the same absolute power of muscle work, but also when performing the same relative power, expressed as a percentage of maximum oxygen intake.

Under the influence of exercise, there is a decrease in the utilization of intramuscular glycogen and blood glucose. In cardiac muscle, this glycogen-protective effect is mediated by the functioning of the glucose-fatty acid cycle, through which increased lipid oxidation leads to the accumulation of intracellular citrate and subsequent inhibition of glycolysis at the phosphofructokinase level.

Reduced blood glucose uptake and utilization by muscle also lowers the degree of glycogenolysis in the liver and provides better maintenance of blood glucose homeostasis during prolonged exercise. The decrease in the rate of carbohydrate oxidation in trained individuals during exercise is correlated with a decrease in the rate of La production. During submaximal aerobic exercise, La concentrations are lower in highly trained athletes than in low-skilled athletes. This is true regardless of whether the intensity of exercise is expressed in absolute or relative values. This effect is due to resynthesis (gluconeogenesis) of lactate to glucose by the liver. In a trained individual, the rate of gluconeogenesis in the liver during exercise becomes higher under the influence of training.

The decreased rate of carbohydrate oxidation and the decreased rate of La production contribute to the limited carbohydrate reserve in the body, because the rate of muscle glycogen utilization under the influence of exercise becomes lower.

Because of the close correlation between the availability of muscle glycogen as an energy fuel and the ability to display endurance, a decrease in the rate of glycogen utilization should be considered as the main factor contributing to the improvement of physical condition in endurance sports.

The changes in substrate utilization that occur under the influence of exercise may also be related to a lesser disturbance of ATP homeostasis during exercise: an increase in mitochondrial functional capacity occurring under the influence of exercise, a smaller decrease in ATP and creatine phosphate and a smaller increase in ADP and inorganic phosphate during exercise to maintain the balance between ATP resynthesis rate and ATP utilization rate.

In other words, as the number of mitochondria increases, the demand for oxygen, as well as ADP and inorganic phosphate, per mitochondrion after exercise becomes lower than before exercise.

It is known that the decrease in carbohydrate oxidation that occurs under the influence of training during muscle work is compensated by an increase in lipid oxidation rate.

These are, in brief, the features of biochemical processes during endurance training.

By changing the intensity of an exercise, its duration, the number of repetitions, intervals and the character of rest, one can selectively select the load according to its preferential influence on different components of endurance. Improvement of motor skills and increase of technical mastery leads to decrease of energy expenditure and increase of the efficiency of bioenergetic potential use, i.e. to the increase of endurance.

Pharmacological support of sports with cyclic structure of physical work performance should be aimed at amplification of positive factors (lipolysis, gluconeogenesis etc).

Basic I - bringing physiological functions and the rate of biochemical reactions to the maximum level.

Basic II - work on special endurance.

Pre-competition - finishing the quality of endurance to the competitive level.

Strength

A person's strength is defined as his ability to overcome external resistance (or actively counteract it) by muscular exertion. That is how strength (as a physical quality) is represented in the general theory and methodology of physical education and sports training.

The force developed by a muscle depends:

On its physiological cross-section;

an activating influence from the CNS;

The ratio of the two main types of fibers in it (strong and fast - white; endurance and slow - red);

external biomechanical conditions (for example, from the parameters of the body, the individual characteristics of exercise technique).

One of the essential moments that determine muscle strength is the mode of muscle work. When overcoming external resistance the muscles contract and shorten - it is the overcoming mode of their work. But muscles can also lengthen under tension - this is the yielding mode. Overcoming and yielding modes are united by the notion of a dynamic mode.

a dynamic mode. At the same time there are very often situations when a person has to show force without any change in muscle length. This mode of their work is called isometric, or static.

Muscles show the greatest strength in static mode, although on the whole this mode is the most unfavorable for the body.

The following varieties are commonly distinguished in the characterization of a person's strength capabilities:

maximal static force is an indicator of strength manifested in resistance to external action or in holding for a certain period of time extreme loads with maximum muscle tension;

slow dynamic (bench-pressing) force is, for example, demonstrated when moving objects of great mass, when the speed of movement is practically of no importance, and the applied efforts reach their maximum values;

fast dynamic force - is determined by the ability of a person to move large (submaximal) loads in a limited time with an acceleration below the maximum;

"explosive" strength - the ability to overcome resistance with maximum muscular tension in the shortest possible time and with the maximum possible acceleration during movements;

cushioning force - characterized by the ability to develop effort in the inferior mode of muscle work in the shortest possible time;

Strength endurance - determined by the ability to maintain optimal force characteristics of movements for a long time.

Training sessions aimed at developing strength, power, speed have little or no effect on aerobic capacity and cause relatively small adaptive changes in the cardiovascular system. This is in accordance with the principle of specificity of sports training.

The increase in muscular strength during the first weeks of strength training promotes the full activation of motor units and muscle groups. The initial rapid increase in strength that is obtained during the first stages of the training process turns out to be unrelated to the increase in muscle size and area of their physiological cross-sectional area.

A longer and more intensive training program aimed at developing strength capacities leads to hypertrophy of muscles, further increase of strength, and decrease of the portion of their maximal contractile activity manifestation. Increased muscle mass means that more muscle tissue is involved in the performance of work, which results in increased ultimate power of the latter and the total energy production of anaerobic systems.

As a result of adaptation of muscles to strength training the following changes occur to them:

hypertrophy of muscle fibers;

increase of anatomical cross-sectional area;

increase in creatine phosphate and glycogen content;

increase in the rate of glycolysis;

increased strength and ability to perform high-intensity exercise;

reduction of mitochondrial density;

improvement of muscle buffering properties.

Relatively short-term weight-bearing exercise or sprinting, which requires the manifestation of a high level of anaerobic metabolism, induces specific changes in the immediate (ATP and CP) and short-term (glycolysis) energy supply systems and improves strength and sprinting ability. The latter include an increase in the maximum power of muscle contractions, the amount of intense work produced in a short period of time, and an increase in the duration of performance (endurance) of high-intensity exercise.

As for the changes concerning aerobic (mitochondrial) enzymes, as a rule, there is a significant hypertrophy of fibers, in which the activity of oxidative enzymes and cytochromes is reduced, probably associated with an increase in the cross-sectional area of muscle cells (mostly type II fibers) without an adaptive increase in the number of mitochondria. In endurance sports the number of capillaries can remain unchanged but their greater surface area between large muscle fibers leads to the decrease of the capillary density per unit cross-sectional area.

Under the influence of anaerobic training during maximal intensity exercise the La concentration in blood can reach high values, which is evidently due to a higher content of intramuscular glycogen and glycolysis enzymes. Strenuous strength training requires considerable motivation and resistance to pain resulting from metabolic acidosis (acidification) due to increased levels of La in the blood.

Increased muscle ability to buffer protons accumulated due to La accumulation may also be important. Type II fibers are characterized by high buffering capacity and their increase indicates an increase in this capacity.

Under the influence of sprint training, there is a significant increase in physicochemical buffering in the muscle when the buffering capacity is calculated based on the pH and La content determined after exercise.

It should be taken into account that these effects are specific for the muscles involved in the implementation of the training program, especially for the individual types of muscle fibers involved in the performance of physical exercise.

Recently, the role of strength, strength capabilities in the manifestation of endurance of highly skilled athletes, their strength endurance, specific local muscular endurance, has been more and more insistently discussed.

An athlete engaged in the development of muscle mass, strength, and strength endurance must be clear about which drugs to take to promote the development, maintenance, and recovery of these qualities.

Speed

The speed ability of highly skilled athletes should be presented as the ability to overcome external resistance in short intervals of time (in other words: quickly, instantly, "explosively") by means of muscle tension, force.

Training sessions aimed at the development of speed are impossible without the development of the quality of force (power), one of its most important components. This is in accordance with the principle of specificity of sports training.

Relatively short-term physical loads with weights or sprinting, which require manifestation of a high level of anaerobic metabolism, cause specific changes in the systems of energy supply, improve sprinting ability.

Sprinting qualities include an increase in the maximum power of muscle contractions in a short period of time, as well as an increase in the duration of high-intensity work.

When sprinting ability improves, it is accompanied by an increase in ATP turnover due to the increased contribution of anaerobic glycolysis to energy supply.

The number and activity of enzymes involved in the glycolytic pathway consistently show a tendency to increase under the influence of both sprinting and strength training with the most pronounced changes in type II fibers.

Coordination

The main focus of pharmacological support of coordination qualities should be to protect against stress and develop the ability to concentrate and improve memory.