PhD N.B. Novikova¹
PhD N.B. Kotelevskaya¹
G.G. Zakharov^1
1St. Petersburg Scientific Research Institute of Physical Culture, St. Petersburg

Keywords: cross-country skiing, tactics, simultaneous starts, pursuit race, elite cross-country skiers, resource management, competitive success.

Background. Modern studies of elite sports by Saint Petersburg Scientific Research Institute of Physical Culture (SPSRIPC) are based on and governed by its old research traditions. It was in July 1969 that the Elite Sport Research Department headed by PhD Valentin Bulkin was established at Leningrad Scientific Research Institute of Physical Culture (LSRPC). In 1970 the LSRPC was nominated an institutional leader and coordinator of the national physical culture and sport research process by the Sport Committee of the Russian Federation. The LSRPC research teams gave a high priority at that time to the excellence training systems for sport elite; training process design and management tools in the multiannual training systems; and the training and competitive performance tests and analyses. The Winter Sports Research Unit at that time was managed by PhD Yevgeny Grozin, one of the founders of the winter sports research school in the former USSR. Many of the active athletes and top professional coaches defended PhD theses under his leadership on a wide variety of sport elite training issues including the physical and technical progress, altitude trainings, competitive performance modeling and progress tests. The Winter Sports Research Unit has successfully developed new training technologies for junior athletes including detailed training systems for ski jumping and Nordic combined. For many years the LSRPC research teams have provided theoretical and practical support to the cross-country skiing, ski jumping, Nordic combined, bobsled and toboggan national teams of the USSR, RF and Leningrad with the combined progress tests of the skiing sport elite in the USSR/ RF Winter Sports Festivals.

In the challenging period of early 1990s, upon breakdown of the USSR, Saint Petersburg Scientific Research Institute of Physical Culture went through the huge outflow of human resource with natural reductions in the research project activity. In 2009, however, a new Winter Sport Elite Training Technologies Development Unit was established at SPSRIPC and a few years later renamed to the Sport Elite Training Technologies Development Unit. Presently the Unit gives a special priority to the research projects to improve the competitive performance standards of the national cross-country skiing elite.

These issues are increasingly topical due to the growing competitiveness in the global cross-country skiing sport on the one hand, and the ongoing globalization processes that largely level down all country differences in the sport inputs, equipment and training systems, on the other hand. It is not unusual nowadays that the high-ranking competitions are won by athletes with little if any real advantages in the physical fitness and skills albeit capable of mobilizing their individual resource at the right time and place. Some analysts hold to the opinion that the high competitive performance standards are secured by the perfect skiing techniques and high-intensity precompetitive trainings [1]. We believe that these factors should not be underestimated although high tactical skills are no less important for success. The very close competitive performance rates of the leading athletes in many disciplines including the relatively new simultaneous-starts, pursuits and sprints, force the sport community to analyze the success factors in the modern cross-country skiing disciplines and give, among other things, a growing priority to a variety of tactical skills including the physical and mental resource mobilizing skills in challenging competitive situations [4, 3, 2]. The national and foreign study reports have given a special attention to novelties in the sport tactics including the physical resource management scenarios for individual cross-country skiing events, albeit such tactics for the modern simultaneous-start and pursuit ski races are still underexplored at this juncture [3, 2].

Objective of the study was to analyze the cross-country skiing tactics of the sport elite for success in the modern simultaneous-start and pursuit races.

Methods and structure of the study. We analyzed the competitive records of the 2017-18 World Cup events to profile the distance speed of the leading skiers in the mass simultaneous and pursuit races; plus PolarV800 test data of the national competitors in these events; and the individual interval-speed-rating snapshots using the video record analysis by Dartfish Pro Suite software tools.

Results and discussion. For the purposes of the study we used a standard statistical toolkit to process the 15/ 30/ 50km competitive records of the 2017-18 World Cup events to obtain and generalize the speed variations of the top 30 competitors in every event followed by the speed variation analysis for the leaders versus the underdogs; and to find correlations, if any, between the interval speed and competitive success rates. Given in Table 1 hereunder are the generalized 15km speed variation data; with the speed deviation from the competitive average per circle (V₁, V₂, V₃) used as the key competitive speed variation rate. Having analyzed the above data, we found that the mass simultaneous and pursuit racing events differ in the individual resource management scenarios on the distance, with the speed normally falling on the second circle, particularly in the mass simultaneous starts. The competitive average speed per circle in pursuit races showed the highest variation range (up to 0.44m/s) in the leaders’ records – versus the underdogs’ variations in the mass simultaneous starts and pursuit races that were notably less expressed – in contrast to the individual ski races where the picture was the opposite [5]. This finding may be explained by the fact that the underdogs have no chances for bonus points plus normally less physically fit for the tactical accelerations when necessary.

Table 1. 15km competitive speed variations in the 2017-18 World Cup events

Note: V₁/ V₂/ V₃ means the first/ second/ third circle speed difference from the competitive average; Δmax means the largest circle speed difference

Given on Figure 1 hereunder is the diagram of the 15km circle competitive speed variations.

Figure 1. 15km circle competitive speed variations for mass starts (MSt) and pursuit races (P) in the 2017-18 World Cup events

Average speed, m/s Circle 1 Circle 2 Circle 3 Circle 4

Kuusamo P Toblach P Val di Fiemm MSt Lencerhaide P Zeefeld NSt

As shown in Figure 1, the average speed tends to sag in the middle-distance intervals to come to maximum in the final intervals, with some variations in the interval speed snapshots over the distance.

The competitive records make it possible to compare the 600m to 2600m interval speed on different circles and analyze them versus the finishing speed. In case of pursuit races, we analyzed correlations of the interval speed with the final results. It was found by the analysis that the competitive success rate was largely dependent on the middle-circle and final-circle speed, with a special contribution of the interval speed on the difficult terrains (with r=0.889 and r=0,884 for the finishing spans at Zeefeld and Kuusamo, respectively). There are good reasons to assume that the leaders prefer the most difficult terrains for the tactical accelerations; whilst in some intervals of the first circles the interval speed to final competitive success ratio was negative – that means that the leaders run slower than the rivals in these intervals for some tactical reasons.

The 30/ 50km competitive speed variations were found rather specific due to the long time (above 75min) of the races and the racing style switchovers in skiathlon. The average speed and speed ranges in the classical-stride intervals were found to fall with every circle; versus the skating-stride intervals where the average speed was maintained virtually at the same level for 3 circles, with the speed range even occasionally increasing. Every competitor showed a significant acceleration on the last circle on the whole and in the finishing interval in particular. The speed variation range was found particularly wide on the first skating-stride circle – that may be due to stride-switchover related adaptation. Given on Figure 2 hereunder are the leaders (top 10) versus underdogs (11 to 30ies) speed variation data for skiathlon event.

It was found that the leaders vs. underdogs speed difference tend to grow in the middle-distance intervals and fall in the finishing interval. On the whole, the speed variation curves are much the same for the pool of competitors albeit the underdogs tend to evenly distribute their energy resource over the distance that means that their circle speed variations are lower than that in the leaders group. Thus the leaders vs. underdogs average speed difference made up 3.98% on Circle 4 and 6.4% on the skate-stride interval.

Figure 2. Leaders’ versus underdogs’ average speed variations in skiathlone

The 50km times varied from 2 hours to 2 hours 30 min depending on the stride, terrain and weather conditions on the one hand, and on the movement efficiency, energy resource management and competitive tactics on the other hand.

Figure 3. Leaders’ versus underdogs’ average speed variations in 50km event

Rules of the 50km marathon competitions allow ski replacements to make the racing tactics more versatile and the average interval speed ratings more difficult. This was the reason why the tactical variations were rated by the interval speed snapshots on the tactically important ascends. It was found that the leaders’ speed variations on the distance were lower than the underdogs’: see Figure 3, with the leaders’ and underdogs’ circle speed differences estimated at 4.87% and 6.53%, respectively.

Conclusion. The study data and analyses show the difference in the speed control patterns in the mass simultaneous and pursuit races. The 15/30km speed variation range were found higher in the leaders’ group versus the underdogs’ group, with the leaders’ 15km circle speed being 3.33-8.35% different – that is much higher than in the individual races. In the 30km event, the leaders’ group speed variation range was estimated at 10.7% and 6.1% for the classical-stride and skating-stride intervals, respectively – in contrast to the 50km event where the leaders’ group speed variation ranges were much shorter than the underdogs’ group.

The study data and analyses may be beneficial for the initiatives to improve the elite cross-country skiers’ training systems. It should be mentioned that most important for success in the simultaneous-start and pursuit races is the ability to speed up on the distance and fast recover thereafter, plus prudently save necessary energy resource for the finishing spurt.

References

1. Myakinchenko E.B., Kryuchkov A.S., Volkov M.V. et al «Sekrety» norvezhskikh lyzhnikov ["Secrets" of Norwegian cross-country skiers]. Teoriya i praktika fiz. kultury, 2017, no. 1, pp. 78-82.
2. Novikova N.B. Obzor inostrannoy literatury po problemam sovremennoy taktiki lyzhnykh khodov [Review of foreign literature on problems of modern skiing tactics]. Sport i sportivnaya meditsina: Mater. Vseros. s mezhdunar. uchastiem nauch-prakt. konf. [Sports and sports medicine: Proc. nat. with intern. participation res.-pract. conf.]. Tchaikovsky: TSIPC publ., 2018, pp. 187-196.
3. Novikova N.B., Kotelevskaya N.B. Analiz dinamiki sorevnovatelnoy skorosti silneyshikh lyzhnikov-gonshchikov v individualnykh gonkakh na etapakh Kubka mira [Study of competitive speed dynamics in the strongest cross-country skiers in individual races at World Cup stages]. Nauka i sport: sovremennye tendentsii, 2018, no. 2 (19), pp. 62-68.
4. Formenti D., Rossia A., Calogiurib G., Thomassenc T.O., Scuratia R., Weydahlc A. Exercise Intensity and Pacing Strategy of Cross-country Skiers during a 10 km Skating Simulated Race Research in Sports Medicine: An International Journal, 2015, no.23, pp. 26-139.
5. Sandbakk Ø. A Reappraisal of Success Factors for Olympic Cross-Country Skiing, HC. Holmberg International Journal of Sports Physiology and Performance, 2014. no. 9, pp. 117-121

Corresponding author: novik-nat@mail.ru

Abstract

The study gives an overview of the winter sports research projects of Saint Petersburg Scientific Research Institute of Physical Culture (SPSRIPC) with a special emphasis on the versatile tactics of the elite cross-country skiers in simultaneous-start and pursuit ski races for the competitive performance improvement purposes. Objective of the study was to analyze the modern cross-country skiing tactics most efficient in contact races. 30 elite national cross-country skiers were sampled for the study of their competitive performance in 11 events of the 2017-18 World Cup finals. The study profiled the interval speed and speed variation ranges in the events including the simultaneous-start and pursuit races to find the speed sagging trend in the middle-distance section and rate accelerations in the final section. The leading athletes were tested with the highest speed variation range on the middle-distance intervals – from 3.33% to 8.35% in the 15km races to 6.1% to 10.7% in the 30km skiathlon. The leaders’ competitive performance was found largely determined by the speed controls on the difficult terrains in the middle to final sections of the distance.

The study data and analyses may be beneficial for the initiatives to improve the elite cross-country skiers’ training systems. It should be mentioned that most important for success in the simultaneous-start and pursuit races is the ability to speed up on the distance and fast recover thereafter, plus prudently save necessary energy resource for the finishing spurt.