STANDARDS OF THE VARIATIONAL RANGE OF CARDIAC INTERVALS AT REST AND DURING AN ORTHOSTATIC CHALLENGE WITH DIFFERENT TYPES OF REGULATION IN SKI RACERS IN THE TRAINING PROCESS

The purpose of the research – to determine, with individual dynamic studies of heart rate variability at rest and during an orthostatic challenge, the standards of the variational range of cardiac intervals (MxDMn), taking into account the type of regulation in ski racers in the training process.

Methods and organization of the research. 559 dynamic studies of HRV (Heart rate variability) at rest and during an orthostatic challenge were conducted in 34 First-Class ski racers aged 17-22 years, Candidates for Master of Sport and Masters of Sport. The research was carried out during different periods of the training process, in the morning after the previous training day and before the first training session of the current day using the Varicard 2.51 device and the Varicard MP program (Ryazan). The predominant type of autonomic regulation was determined according to the classification proposed by N. I. Shlyk [6,7,9,10,11,12].

The results of the research. When analyzing 559 HRV studies, seven ranges of the value of the variational range of cardiac intervals were determined: <150 ms, 151-250, 251-350, 351-450, 451-550, 551-650 and >650 ms. The standards of HRV indicators at rest and during an orthostatic challenge in ski racers at different ranges of the MxDMn value were compiled. Respiratory HF waves or vasomotor LF waves prevailed apart from training process periods. Unfavorable ranges of the MxDMn value at rest in the morning were revealed, accordingly the quality of the sinus node is disrupted, the vegetative balance changed, the recovery and reactivity of the body deteriorated. The frequent change in the value of MxDMn at rest from a favorable range to an unfavorable one, as well as the constant presence of unfavorable ranges of MxDMn in athletes in the training process, combined with a paradoxical reaction to orthostasis, are associated with individual instability of the recovery processes and the state of cardiac regulatory systems due to a discrepancy in the functional readiness of the body to perform training loads, leading to overtraining.

Conclusion. According to the results of the study, new scientific data were obtained on the standards of the variation range of HRV cardiac intervals at rest and during an orthostatic challenge in ski racers, taking into account the type of autonomic regulation, the predominance of respiratory (HF) and vasomotor waves (LF), which were important for detecting and preventing the earliest violations of cardiac regulatory systems, the work of the sinus node, recovery processes, overtraining and prediction of sports results.

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