PhD N.B. Novikova¹ 
I.G. Ivanova¹
PhD, Associate Professor G.A. Sergeev²
Graduate student A.V. Petrushin²
PhD (Medicine), Associate Professor N.K. Golubeva^3
1Saint-Petersburg scientific-research institute for physical culture
²Lesgaft University, St. Petersburg
³I.M. Sechenov First MSMU MOH Russia (Sechenovskiy University)

Key words: skiing technique, kinematic characteristics
Biathlon is a sport, where success is determined by time in cross-country skiing and results in shooting. The tactics of the ski race, the choice of an effective method of movement and the optimal pace are the reserve for increasing the effectiveness in biathlon [1]. Probably, the analysis of biomechanics of the ski run of biathletes will reveal the reserves of technical and tactical skill. Purpose of the work: to determine the main biomechanical characteristics of biathletes' two-step skating course. Methods and organization. The study involved 10 highly skilled cross-country skiers (27.6 years old) and 11 biathletes (27.1 years old). Studied 3 cycles of movements of the simultaneous two-step stroke. Biomechanical characteristics were calculated using the Dartfish Pro 9 software. The following were determined: movement speed, pace, stride length, duration of crouching, take-off and rolling on one ski, angular characteristics of the main phases of movement. Data processing, analysis and visualization were performed using the Rstudio program [2]. The hypothesis of the significance of the differences was tested using the nonparametric Mann-Whitney test for independent samples. Quantitative data are presented as Me - median, Q1, Q3 - lower and upper quartiles, respectively. Research results. Skiers and biathletes show the highest speed on the starting lap, biathletes reduce their speed on the second and third laps, skiers at the finish lap increase it significantly. An increase in the speed of skiers is accompanied by both an increase in the frequency of movements and the length of the stride, and the values of the stride length of skiers and biathletes in the first and third circles have significant differences. Conclusions: it is likely that an increase in the distance speed is possible due to the use of more uniform options for the distribution of forces and the economization of the technique of movements at the beginning of the distance.

REFERENCES

1. Skattebo, Ø., and Losnegard, T. (2017). Variability, predictability and race factors affecting performance in elite biathlon. Int. J. Sports Physiol. Perform. 13, 313–319.
2. R Core Team (2020). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https: www.R-project.org.