HEART RATE VARIABILITY STANDARDS AT REST AND ORTHOSTASIS AT DIFFERENT MxDMn VALUES AND THEIR CHANGE IN BIATHLETES DURING THE TRAINING PROCESS

Abstract

Aim. The paper aims to elaborate standards for HRV at rest and orthostasis based on the results of an individual dynamic express study of heart rate variability (HRV) in biathletes, taking into account high variability within HRV ranges (MxDMn). The paper also aims to identify the features of their change in the training process in case of disturbance of regulatory systems and sinus node, recovery processes, overtraining and performance reduction. Materials and
methods. Dynamic studies of HRV at rest and orthostasis were carried out in 90 biathletes ages 17–22 (1^st adult category, Candidate for Master of Sport, Master of Sport) in different periods of the training process. HRV studies were carried out in the laboratory of the biathlon school (Sports Training Centre for the Udmurt Republic Representative Team, Izhevsk) in the morning in the recovery period after the previous training day before the first training. The studies were conducted using the Varicard 2.51 equipment and the Varicard MP program (Ryazan). Results. In individual analysis of HRV data at rest in biathletes, great importance was attached to the variation range of cardiac intervals (MxDMn), which reflects the state of regulatory systems and the sinus node.
As a result of 2170 HRV studies in biathletes, seven ranges of MxDMn values were determined: < 150, 151–250, 251–350, 351–450, 451–550, 551–650 and > 650 ms. Based on these ranges, HRV standards at rest and orthostasis were elaborated for different cardiac regulation. Conclusion. According to the research results, HRV standards at rest and orthostasis were elaborated for MxDMn values characteristic of the predominant type of autonomic heart rate regulation. New scientific data were obtained on HRV standards in biathletes, which are important for the training process and can be a reference for physiologists, coaches and other researchers.