The article notes that the development of oxidative stress and the violation of cellular energy balance is the primary link of the vast majority of systemically-forming homeostatic shifts in the athlete’s body and changes the vital structure and function of cellular and subcellular proteins membrane. Changes in the quantitative and qualitative composition of lipid components of membranes, inhibition of the activity of key glycolysis enzymes, as well as the deterioration of bioenergy mechanisms, result from the accumulation of free radicals due to activation of lipid peroxidation. The protection of the organelles responsible for energy supply from oxidative effects is provided by mitochondrial disconnecting proteins that exist in the myocardium. The development of metabolic ischemia due to the imbalance between the delivery of oxygen to cardiomyocytes and their need for myocardium is accompanied firstly by the inhibition of the process of oxidation of glucose and an increase in the use of fatty acids, and then the accumulation of lactate with the development of acidosis of the intracellular environment and the impairment of the ability of myocytes and cardiomyocytes to relaxtion and contraction. It has been established that strenuous muscle activity leads to the formation of a hypoxic state with its characteristic redistribution and increase of energy, metabolic, structural resources of the body in the interests of the tissue where adaptive adjustments are taking place. The insufficiency of energy generation due to the development of this state leads to the dysfunction of the mitochondrial apparatus, which subsequently causes the violation of the energy supply, antioxidant protection, membrane stability due to intensification of lipid peroxidation and leads to cell apoptosis. This forms a background for the occurrence of fatigue and tension, followed by reduction of physical performance of athletes. The detection of the above changes makes it possible to prevent and correct in a timely manner the negative effects of oxidative stress associated with ultra-intensive physical loads.

Ilgamečiai didelio meistriškumo futbolo komandų raidos stebėjimai parodė, kad šalies čempionato vykdymas dviem makrociklais turi savitus mokomojo treniruotės proceso planavimo ypatumus. Kiekvienoje šalyje, o ypač Kazachstane, pasireiškia savitos, specifinės futbolininkų sporto treniruotės planavimo metiniu treniruotės ciklu sąlygos. Šio darbo tikslas buvo konstatuojamojo eksperimento pagrindu išnagrinėti ir palyginti Kazachstano aukščiausiosios lygos futbolo komandos treniruotės ir varžybų proceso struktūrą bei turinį, esant įvairiems metinio treniruotės ciklo variantams. Buvo ištirta Kazachstano profesionalaus futbolo klubo „Aktobe“ sportinio rengimo technologija įvairiais metinio ciklo etapais. Atsižvelgiant į šalies futbolo varžybų kalendorių, komandos rengimas vyko pagal du metinio ciklo planavimo variantus. Viename sezone komanda žaidė tik šalies čempionate ir šalies taurės varžybose (I variantas), kitame sezone – be šių varžybų, komanda dar žaidė UEFA čempionų lygoje (II variantas). Metinėje futbolininkų rengimo programoje buvo skaičiuojama pratybų skaičius, jų trukmė, buvo sudaromas fizinio krūvio skirstinys pagal energijos gamybos zonas. Futbolo komandos fizinio krūvio, atlikto metiniu ciklu, parametrų analizė parodė, kad jis atitinka profesionalaus futbolo klubo žaidėjams keliamus reikalavimus ir gali būti vertinga informacija planuojant didelio meistriškumo futbolo komandų rengimą. Bendra treniruotės ir varžybų fizinio krūvio apimtis, esant skirtingiems metinio rengimo ciklo sudarymo variantams, yra skirtinga. Pirmuoju atveju ji siekia 834 val., o antruoju – 926 val. Galima pažymėti, kad krūvio apimtis pirmuoju metinio ciklo sudarymo atveju antrame čempionato rate padidėja nuo 312 iki 324 val., o antruoju atveju padidėja nuo 322 iki 408 val. Vadinasi, antruoju metinio ciklo sudarymo atveju, kai komanda dalyvavo UEFA lygos čempionate, treniruotės krūvio apimtis sumažėjo, o varžybų – padidėjo. Esant skirtingiems metinio treniruotės ciklo sudarymo variantams, kai dalyvaujama tarptautiniuose turnyruose, organizmas patiria didesnius fiziologinio pobūdžio pokyčius, nes daugiau atliekama aerobinio-anaerobinio ir anaerobinio alaktatinio poveikio fizinio krūvio.

Currently, according to the conception of children and youth football development in Kazakhstan, there has been a harmonious system formed to train young football players. The trainings are implemented by football departments of children and youth sport schools and specialized children and youth sport schools of Olympic Reserve. Recently, specialized football classes are getting widely expanded as a compulsory part of general education in many countries. However, there have not been designed sufficient methodical recommendations for teachers and coaches about the organization of training processes and rationalizing work load in specialized football classes up to now, in order junior football players to progress in specialized classes, it is necessary to draw the daily regulations properly and to define the content of physical training curriculum for different age groups. However, there are considerably scarce data available on this issue. Moreover, fluctuation of physiological functions in physical activities performed by young football players in learning conditions in specialized classes have not been sufficiently studied yet. The purpose of this study is to determine the pulse rate of physical exercises and technical trainings fulfilled by young football players in learning conditions in specialized classes. The research study involved 25 young footballers of age 15-16 from specialized classes of secondary schools in Almaty, Kazakhstan. Those young football players’ cardiovascular system reaction was defined via radio telemetry device Sports Tester that recorded average heart rate (HR), its minimum and maximum values, the sum of heartbeat during training and game, and its allocation within different physical activities. Aerobic capacities were determined using indirect method when doing physical load for 5 minutes on a veloergometer Kettler with power of 150W. The maximum oxygen consumption (VO2 max) was estimated by the Astrand (1960) test. In accordance with the age of subjects, the results were correlated with the coefficient (r=1,1). The data was analyzed using methods of mathematic statistics. The results of the research study showed that determining the pulse rate of cardiovascular system activities performed by young football players measured via radio telemetry device which helped to observe the reaction of athletes’ organism to different physical loads during whole physical training classes. It is significant to mention that higher reaction of cardiovascular system in physical activities are noted in carrying out repeated game exercises within technical trainings at a quarter of the pitch without the goal areas with 2 x 2 players, also 6 x 6 players. Among physical activities of young football players, the most intensive work of cardiovascular system requires launch acceleration for 2 minutes, running jumps and outdoor games. The conducted analysis using radio telemetry registered players’ heart rate (HR), defined the pulse rate of separated parts of training and competitive activities. Received data allows coaches to classify training loads in intensity zones which help them correlate training curriculum of young football players. Thus, present research data as well as other authors’ works fills the gap in the area where physical loads of young football players’ functional systems are of studies matter.