Физическая активность и здоровье

Sports and physical activities -2

In the structure of the athlete’s coordination abilities, first of all, it is necessary to distinguish the perception and analysis of their own movements, the presence of images, dynamic, temporal and spatial characteristics of the movements of their own body and its various parts in their complex interaction, understanding the motor task set, forming a plan and a specific way of performing the movement. With all these components, effective effector impulses of muscles and muscle groups can be provided, which need to be involved in highly effective movement performance from the point of view of coordination. An important factor determining the level of coordination is also the operational control of the characteristics of the performed movements and the processing of its results. In this mechanism, a special role is played by the accuracy of afferent impulses coming from the receptors of muscles, tendons, ligaments, articular cartilage, as well as visual and vestibular analyzers, and the efficiency of their processing by the central nervous system.

Considering musculoarticular sensitivity as the most important prerequisite for the effectiveness of afferent impulses, we should note the selectivity of its formation in strict accordance with the specifics of sports, the technical arsenal of a particular athlete.

The level of coordination abilities largely depends on motor (motor) memory — the ability of the central nervous system to remember movements and reproduce them if necessary. An important factor determining the level of coordination abilities is effective intramuscular and intermuscular coordination. The ability to quickly activate the required number of motor units, ensure optimal interaction of synergistic and antagonistic muscles, and quickly and effectively transition from muscle tension to muscle relaxation is inherent in qualified athletes with a high level of coordination abilities.

Гуляйте на здоровье! Почему физическая активность должна войти в привычку каждого из нас - DELFI

The most important element of the athlete’s coordination abilities is the perfection of the mechanism of neuromuscular impulse transmission, which provides for the possibility of increasing the impulse of motor neurons, recruiting additional motor neurons-in some cases, reducing the impulse of motor neurons, reducing the number of motor neurons that send impulses-in others.

Endurance is the ability to effectively perform physical activities, overcoming developing fatigue. In the most general form, fatigue is characterized as a reversible violation of physiological and biochemical homeostasis, which is compensated in the post-loading period.

Endurance is measured by time and directly depends on the intensity of the load performed. The level of endurance development is determined by the energy potential of the athletes ‘ body and its compliance with the requirements of the sport. Endurance is divided into general and special, training and competitive, local, regional and global, aerobic and anaerobic, alactate and lactate, muscle and vegetative, sensory and emotional, static and dynamic, speed and strength. The specifics of endurance development in sports should be based on the analysis of factors that limit the level of manifestation of this quality in competitive activities, taking into account the requirements for regulatory and executive bodies.

In sports physiology, the term “endurance” includes two separate but interrelated concepts-muscular and cardiorespiratory endurance, the meaning of each of which varies in different sports.

Muscular endurance is especially characteristic of runners. It is expressed in the ability of an individual muscle or group of muscles to withstand a load for a long time — repetitive (running) or static (weightlifting, wrestling). In this case, muscle activity can be rhythmic or repetitive (boxing) or static (wrestling). Muscle endurance is closely related to muscle strength, anaerobic and aerobic performance. It is possible to study muscular endurance both statically and dynamically, using free weights and isokinetic devices in a bench experiment. An indicator of static endurance is the time that an athlete can hold a certain mass, and it is associated with absolute muscle strength. An indicator of dynamic endurance is the number of repetitions performed with a certain resistance during a certain time. Speed and strength endurance of the hands is evaluated by performing a five-minute maximum muscle work. The recorded indicators allow you to calculate the mechanical power of work and the power of a single movement.

Cardiorespiratory endurance is related to the ability of the body to withstand a long cyclic load and characterizes the capabilities of the entire body as a whole. This type of endurance is typical for runners, cyclists, and swimmers who cover long distances at relatively high speeds. Cardiorespiratory endurance depends on the development and functioning of the cardiovascular and respiratory systems and is characterized by the aerobic capacity of the body. For load testing for this type of endurance, a continuous, stepwise increasing load is used without rest intervals, at which cardiorespiratory indicators reach a stable state in each stage. To conduct tests in a bench experiment, use a bicycle ergometer or treadmill.

Физическая активность и мозг | Наука и жизнь

Samples with pharmacological markers

Based on the above, samples with cardiovascular drugs were developed and an assessment of samples affecting cardiorespiratory endurance was given (Karpman et al., 1983). These drugs affect the conductivity (CSl, amyl nitrite) of impulses in the Giss bundles, on the coronary vessels and the autonomic nervous system (atropine, anaprilin, inderal).

According to the principle of pharmacological testing, these samples are usually divided into load and shutdown samples. Stress tests include tests in which the pharmacological preparation used has a stimulating effect on the physiological or pathophysiological mechanism under study.

In different sports, endurance is determined by the same physiological and biochemical mechanisms that need to be analyzed in the study of individual types of sports loads and the effect of various medications on their tolerance. The test procedures used in practice should provide an assessment of the indicators of endurance (working capacity).) and bioenergetic capabilities of an athlete in standard conditions of a laboratory experiment and quantify the degree of implementation of these indicators in specific conditions of competition in individual sports. In the practice of monitoring the development of endurance athletes , standardized ergometric tests are now widely used, which allow us to obtain quantitative estimates of performance or power, aerobic and anaerobic capabilities.

Along with recording ergometric indicators of endurance, direct measurements of bioenergetic parameters of power, capacity, and efficiency of aerobic and anaerobic capabilities are important for the selective assessment of individual components of this quality. As you know, the functional capabilities of an athlete depend to a large extent on their aerobic and anaerobic performance. Aerobic performance is determined by a number of factors that ultimately contribute to the fastest delivery of oxygen to tissues and its efficient use. The main indicator of the effectiveness of the cardiorespiratory system is the maximum oxygen consumption (BMD or V02max) — the maximum amount of oxygen that a person is able to consume within one minute or the maximum intensity of its utilization in the event of extreme debilitating exercise.

When intense muscle activity occurs at a certain stage, there is a discrepancy between the oxygen demand of the working muscles and its delivery. Under these conditions, oxygen-free (anaerobic) energy supply pathways are activated. Accumulation of under-oxidized metabolic products (metabolites of carbohydrate and lipid metabolism) leads to a violation of the acid-base state of the blood, a decrease in the capacity of buffer bases and blood pH. Elimination of acidic metabolites is associated with increased oxygen consumption during the recovery period. This excess amount of oxygen consumption compared to the resting level is called total oxygen debt (CD), so the CD value is determined by the number of metabolites of anaerobic metabolism. Anaerobic performance of an athlete depends both on the ability of tissue systems to generate energy under hypoxic conditions, and on the ability of the athlete to continue working with critical changes in the pH of the internal environment of the body. Among the most valid physiological and biochemical parameters that serve as estimates of the power, capacity, and efficiency of aerobic and anaerobic processes, first of all , direct measurements of BMD, CD, maximum lactic acid accumulation in the blood, and the greatest shift in blood pH should be indicated.