Dr.Med. A.L. Pokhachevsky¹
E.V. Maltusova¹
PhD V.N. Zakopyrin²
PhD A.B. Petrov^3
1I.M. Sechenov First Moscow State Medical University of Russia, Moscow
²Academy of Federal Penal Service of Russia, Ryazan
³Lesgaft National State University of Physical Education, Sport and Health, St. Petersburg

Key words: heart rate, exercise tolerance.

Introduction. The prognostic possibilities of early heart rate variability with unsatisfactory physical activity, which determine the probabilistic maximum of exercise tolerance and the subsequent recovery period, do not lose relevance in either sport or cardiology.
Purpose of research was to establish the possibility and determine prognostic markers of recovery after maximum physical exertion by the early variability of the heart rhythm (SR) of the loading period.
Methodology and organization of research. A sample (37 people) of practically healthy young people aged 18-23 years of mass categories, cyclic sports was examined. The maximum bicycle ergometric testing (e-Bike Ergometer) was carried out according to an individual protocol [1]. From the digitized (PolySpektr-12, Neurosoft) electrocardiogram of the entire testing time, a consecutive series of RR intervals (cardiointerval – KI) —the cardiac rhythmogram (KRG), was distinguished.
The mathematical model of the KRG of the load period was constructed as Y = a / X + b, where X is the serial number of the CI, Y is its duration, “a” is the model parameter characterizing the variability of the time series, and “b” is the model parameter determining its constant component . The optimization of the models was achieved by the least squares method [1]. The time series of the KRG of the early adaptation period (RAP) were subjected to mathematical modeling: 1, 2, and 3 min of the load and recovery periods. Due to the difference in the distribution of the obtained values ​​from the normal one, the data were presented as a percentile series.
Research results and discussion. Load KRG RAP has significant connections with the entire recovery period of the stress test. However, the 2nd min of recovery demonstrates most of all the interconnections, revealing them both by the severity of variability (indicator of the model “a”) and by the constant component “b”. At the same time, at the 1st and 3rd min, communication restoration is determined solely by the “b” indicator, reaching the maximum value of communication (0.75) at the 3rd min. The physiological meaning of this phenomenon: less variability of the KRG (since the model is hyperbolic, you can’t call it speed, although, in fact, it is the same thing) and less heart rate in the first minutes of the load - corresponds to more variability of the KRG and less heart rate of recovery after reaching the load maximum.
Fundamentally new in this study is the fact of revealing a significant relationship between recovery and variability of the CRG of the run-in stage (50 Watt) and the passive stage lasting 30 seconds before the load, showing the stage of complete afferent synthesis of the functional system of maximum bicycle ergometry.
Output. The forecast of recovery can be made not only by the variability of the KRG RAP, but also by the previous exploitation period and the start of the wait.

Bibliografy

1. Lapkin M.M. The value of the variability of cardio intervals during stress testing / M.M. Lapkin, A.L. Pokhachevsky // Human Physiology. - 2017. - No. 1 (43). - pp. 81-88.