Functional reserves and reliability of controlling stereotyped motions of different coordination structures in athletes during muscular activity

Objective: determination of evaluation criteria for functional reserves and functioning reliability of the system of controlling stereotypically repetitive movements in different states during muscular activity in athletes - weightlifters and cyclists.

Material and methods: Highly skilled athletes aged 20-28 years specialized in weightlifting and cycling participated in various studies. A complex methodology was used to study the mechanisms of controlling acyclic speed-strength motion and the morphofunctional status of the body of weightlifters. In accordance with the algorithm of the developed methodology, athletes performed vertical jumps of maximum height on a tensodynamometric platform to a state of persistent work capacity decrease. Developed efforts during jumping, electromyogram of the lower extremity muscles, and HR were recorded. To study the mechanisms of cyclic motion control, the methods of bicycle ergometry were used. In the process of bicycle ergometry, efforts in the pedaling cycle, heart rate, electromyogram of the lower extremity muscles were registered.

Results: It was revealed that under stable conditions of controlling speed-strength and cyclic motions, a rigid, programmatic mechanism of motor regulation is manifested. With the stability of the external (kinematic) structure of the motions performed in different periods of work, only certain parameters of its regulation tend to change: muscular activity and intermuscular interactions. They are indicative of compensatory rearrangements in the internal structure of movements, which ensure the stability of their external structure in a steady state and in the phase of compensated fatigue. In the phase of decompensated fatigue, muscular activity changes significantly, intermuscular relationships are disturbed, physical work capacity decreases. The use of biopsy, histo-, and cytochemistry, light and electron microscopy allowed determining morphological changes in skeletal muscles in the dynamics of muscular performance manifestation in the training process of weightlifters.

Conclusions: The leading criteria for the reserve capacities of the system of controlling stereotyped voluntary motions in athletes are: stability and reliability of maintaining the qualitative parameters of voluntary motions within the optimal range in various physiological states during muscular activity; power, interference immunity, efficiency and interchangeability of compensatory responses providing the functioning reliability of the system of motion control (control according to the principle of equifinality); increasing the role of the program mechanism in the system of voluntary motion controlunder stable conditions of its realization.