The purpose of this study was to examine the dynamics of developing the overcoming fatigue during a strenuous muscular activity of submaximal and moderate power. Material & methods: The study involved 64 elite cyclists examined in laboratory conditions. Activities of moderate and submaximal power were modeled. The bioelectrical activity of cyclists' lower extremity muscles and the dynamics of kinematic and dynamic characteristics were examined, as well as the peculiarities of manifesting balance and mobility of nervous processes. The parameters of gas exchange, external respiration, indices of diffuse conductivity, systolic volume, pulse, arterial blood pressure, etc. were determined. Results: Studies have confirmed the existence of a period ofovercoming fatigue during intense muscular activity and the heterogeneity of this state course. Conditionally overcoming fatigue is divided into three phases: initial, intermediate, and final. The specific character of overcoming fatigue during intense muscular activity is due to a change in the interaction of central nervous impacts and peripheral factors. They determine the quality of regulating the body somatic and autonomic functions, the aspiration of the regulatory systems to maintain high work capacity at the expense of volitional efforts at increasing levels of physiological system functioning. This is accompanied by the inclusion of intramuscular, intrasystem, and intersystem mechanisms for work capacity maintenance, various mechanisms of intracellular metabolism. The peculiarities of the period of overcoming fatigue are determined by the functional stability of the nerve centers, their ability to rebuild regulatory mechanisms and propel the body systems to the next level of functioning. Active inclusion of compensatory intra- and intersystem mechanisms during the period of overcoming fatigue occurs in the face of a progressive decrease in the efficiency and economy of the system functioning. The sharp decrease of the functional economy is not the only cause of the apparent fatigue that induces the decrease of work capacity. It reflects the sum of accumulated overcoming functional and metabolic difficulties, the state of the vegetative centers. Conclusions: Compensatory responses to overcome fatigue are aimed at activating mechanisms that provide increased excitation in the motor cortical centers while maintaining a high tone of the cortical structures. In addition, they contribute to maintaining the maximum level of the respiratory system functioning, circulation, and other mechanisms that ensure the maximum possible oxygen supply to working tissues, the maximum level of oxygen utilization from the blood, respiratory compensation for metabolic acidosis, and the maximum mobilization of anaerobic energy supply sources.
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