In the modern world with the advent of devices that facilitate work (computer, technical equipment) has decreased sharply motor activity of people compared to previous decades. This, in the end, leads to a decrease in human functionality, as well as various diseases. Today, purely physical work does not play a significant role, it is replaced by mental. Intellectual work dramatically reduces the efficiency of the body. Lack of human energy expenditure leads to inconsistencies in the functioning of individual systems (muscular, skeletal, respiratory, cardiovascular) and the body as a whole with the environment, as well as reduced immunity and impaired metabolism.
Exercise affects all muscle groups, joints, ligaments, which become strong, increase muscle volume, elasticity, strength and rate of contraction. Increased muscle activity forces the heart, lungs and other organs and systems of our body to work with additional load, thereby increasing the functional capabilities of man, his resistance to adverse environmental influences. Regular exercise primarily affects the musculoskeletal system, muscles. When you exercise, the muscles generate heat, to which the body responds by increased sweating. During exercise, blood flow increases: the blood brings oxygen and nutrients to the muscles, which in the process of life break down, releasing energy. When movements in the muscles additionally open reserve capillaries, the amount of circulating blood increases significantly, which causes an improvement in metabolism. In response to the reaction of the human body to exercise, the first place is occupied by the influence of the cerebral cortex on the regulation of the functions of the basic systems: there is a change in the cardiorespiratory system, gas exchange, metabolism, and others. Exercises enhance the functional restructuring of all parts of the musculoskeletal system, cardiovascular and other systems, improve tissue metabolism. Under the influence of moderate physical activity increases the efficiency of the heart, hemoglobin and red blood cell count, increases the phagocytic function of the blood. Improves the function and structure of the internal organs, improves chemical processing and promotion of food in the intestine. The combined activity of muscles and internal organs is regulated by the nervous system, the function of which is also improved by regular exercise.
If the muscles do not work - their nutrition deteriorates, volume and strength decrease, elasticity and resilience decrease, they become weak, sluggish. Restrictions in movement (hypodynamia), passive lifestyle lead to various pre-pathological and pathological changes in the human body. So, the American doctors, having deprived volunteers of movements by imposing of high plaster and having kept to them a normal diet, were convinced that in 40 days at them muscle atrophy began and fat has accumulated. At the same time increased the reactivity of the cardiovascular system and decreased basal metabolism. However, during the next 4 weeks, when the subjects began to move actively (with the same diet), the above phenomena were eliminated, the muscles were strengthened and hypertrophied. Thus, due to physical exertion, recovery was possible both in functional and structural terms. Exercise has a multifaceted effect on the human body, increasing its resistance to adverse environmental influences. For example, physically trained people have better tolerance to oxygen starvation than untrained people. High ability to work at increase of body temperature over 38 ° C during physical exertions is noted. It has been noticed that radiologists who exercise have a lower degree of influence of penetrating radiation on the morphological composition of the blood. Animal experiments have shown that regular muscle training slows the development of malignant tumors.
Regular exercise in physical education promotes good health and affects the various physiological adaptations of the neuromuscular, cardiovascular and respiratory systems of the human body. Types of physical activities are considered: aerobic, anaerobic, interval and hypoxic physical activities.
MYOKINES, THEIR ROLE IN MUSCLE CONTRACTION
