Abstract
Purpose. Creation of an informative methodology for testing speed abilities of ice hockey players, based on the characteristics of sprints (duration, distance, speed), performed by the professional ice hockey players in the KHL regular championship games.
Subjects. 20 professional hockey players of the KHL team “Ak Bars” Kazan aged from 22 to 40 years old.
Results. More sprints in one period and in a game are performed by defenders. Most often, both forwards and defenders sprint 1.0-1.9 seconds - this occurs in 68-69% of cases, sprints lasting 2.0-2.9 seconds are found in 22-23%, duration 3.0-5.9 seconds - in 9-10%, and accelerations over 6 seconds are not found at all. Defenders equally often (41%) sprint both 2.0-5.9 and 6.0-10.9 meters. Forwards more often sprint 6.0-10.9 meters - in 44% of situations against 35% at a shorter distance of 2.0-5.9 meters. At a distance of 11.0-15.9 meters, forwards sprint in 14% of cases, and defenders - in 12%. On distances over 16 meters both forwards and defenders sprint quite rarely - in 6-7% of cases.
Conclusion. The most informative tests for assessing speed abilities of ice hockey players are 5 and 10 meters sprints. The use of standard 30 meters sprint test, which is widely used in ice hockey, is justified in the absence of timing gates.

Introduction

Skating on-ice is one of the fastest locomotor activities. Thus, NHL hockey players reach speeds over 32 km/h during games [1]. Speed is one of the key aspects of physical abilities of hockey players [2, 3]. In particular, it was confirmed by a study [4], during which it was revealed that competitive activity is supplied 31% by aerobic energy system and 69% by anaerobic. Add here constant collisions, hits and a puck which moves with speed exceeding 150 km/h, and we get one of the most dynamic sports – hockey. Training process for the sport that places very high demands on the level of preparadness should also be special. At this stage of the development of theory of sports, the means and methods of improving speed abilities are the best developed for track and field sprinters. Hockey, on the other hand, is much more unpredictable: athletes have to constantly respond to a variety of stimuli, accelerate and sprint over different distances both along a straight trajectory and along a curved one. Aforementioned significantly complicates the process of scientific research of the skating characteristics of hockey players. This is probably the reason why scientific data on this topic is scarce.

For example, in one study it was shown that the maximum speed of the NHL players is 40 km/h on average, but players spend only 20% of their playing time at speeds over 20 km/h [5]. In turn, Yu.V. Nikonov in his book "Physical training of hockey players" claims that a hockey player during a game "performs up to 50 accelerations 10-30 m or more at maximum speed <…> the total length [of accelerations at maximum speed – author's note] per game is 1600-1800 m" [6]. Unfortunately, the phrase "10-30 m or more" is vague, and secondly, there is no reference or explanation in the book where this data came from, how was is defined that the speed was truly maximum, or how the distance was measured. There are also studies on optimal skating technique based on biomechanical investigations [7, 8].

Most of research was focused on identifying the correlation between various on- and off-ice tests and on the possibility of transferring from a track or gym to ice [4, 8, 9]. Thus, J.M. Janot and colleagues revealed strong correlation between the tests: 36 m sprint, vertical jump and 45 m on-ice sprint [4]. At the same time, there was no significant correlation between off-ice exercises and 6 m on-ice sprint, as well as flying 15 m on-ice sprint. In the study by C.M. Farlinger et al. [10] the greatest correlation of the 35 m on-ice sprint was observed with 30 m off-ice sprint, tripple long jump, as well as broad jump.
Based on the results of the two studies described above, it can be concluded that the authors have identified the possibility of predicting maximum on-ice speed based on the results of off-ice testing. The negative point in these results is that in real competitive activity, hockey players extremely rarely accelerate over distances 35+ m and develop maximum speed, which will be proved below. Therefore, research on starting speed in hockey will be much more valuable for practical application.

U. Zankovets and V.P. Popov [11] revealed strong correlation between 5 m on-ice sprint, which characterizes acceleration and is specific to the real competitive activity of hockey players, and 30 m off-ice sprint. In addition, moderate level of interconnection was registered between the tests 5 m off-ice sprint, flying 10 m off-ice sprint (20 - 30 m), isometric deadlift and broad jump.
Unfortunately, the above results are not enough. It is well known that in order to design an efficient training program, the coach must take into account such factors as gender, age, and training status of athletes. Period of preparation, time budget and other circumstances should also be considered [12, 13]. Usually, for high-class coaches it is not a serious problem. However, in order for speed training to meet the specifics of the chosen sport, it is necessary to answer the following questions before designing a training plan [14, 15]:

• What distances do athletes usually cover?
• What is the typical duration of sprint?
• What speed is reached?
• How many sprints must be performed per period, game?
• In which direction(s) movement is taking place?
• From which position do athletes usually accelerate?
• What combinations of movements are common?

In this study we are going to find answers to the first four questions in the context of hockey, which cannot be obtained only by the method of pedagogical observation.

Methodology

Purpose: creation of an informative methodology for testing speed abilities of ice hockey players, based on the characteristics of sprints (duration, distance, speed), performed by the professional ice hockey players in the KHL regular championship games.

Subjects: 20 professional KHL players of the Ak Bars hockey team aged 22 to 40 years. 8 of them are defencemen, 12 – forwards.

Study design: from September 1, 2018 to February 22, 2019, all sprints performed by the hockey players of the Ak Bars during 60 games of the KHL regular season 2018/2019 were analyzed. Sprint analysis was performed of the players who participated in at least 30 full games. A full game means that a hockey player was engaged in all three periods of the match. The games were filmed using three FLIR PointGrey GrassHopper3 U3 28S4C video cameras, each filmed one of the three zones of the hockey field. The number of sprints, its duration, distance and speed was analyzed using the Iceberg Sports Analytics system.

Results

During 60 games 135 424 sprints were registered. On average, defencemen perform more sprints per period and per game (Figure 1). This is an interesting point because there is an opinion in the hockey community that defenders are usually not so fast as forwards. However, this need to sprint more often is explained by the fact that defencemen appear on ice more frequently (Figure 2) and, accordingly, have a bigger ice time.

If we consider duration of sprints (Table 1), it turns out that most often, hockey players are sprinting 1.0–1.9 seconds, this happens in 68-69% of cases; sprints lasting 2.0-2.9 seconds occur in 22-23%; duration 3.0–5.9 seconds – in 9-10%, and sprints over 6 seconds do not occur at all. Hence, development of speed abilities in the training process should be mainly focused on sprints under 6 seconds. Total duration of sprints is also a helpful information for coaches for efficient speed endurance development.

Duration of Sprints	Forwards per Period	Defencemen per Period	Forwards per Game	Defencemen per Game
1.0 - 1.9 sec	30	35	91	104
2.0 - 2.9 sec	10	11	29	34
3.0 - 5.9 sec	4	5	13	14
6.0-10.9 sec	0	0	0	0
Total duration (sec)	81	90	242	271

From a distance standpoint, a clear difference between positions is present (Table 2). Thus, defenders equally often (41%) sprint 2.0-5.9 m and 6.0–10.9 m. Forwards more frequently sprint 6.0–10.9 m (44%) comparing to a shorter distance 2.0–5.9 m (35%). A sprint distance 11.0–15.9 m is encountered by forwards in 14% of cases, by defencemen - in 12%. It is quite rare for both positions to sprint over 16 m (6-7%).

Distance	Forwards per Period	Defencemen per Period	Forwards per Game	Defencemen per Game
2.0 - 5.9 m	15	21	46	64
6.0 - 10.9 m	19	21	58	63
11.0 - 15.9 m	6	6	18	17
16.0 - 20.9 m	2	2	7	5
21.0 - 30.9 m	1	1	4	2
Mean distance (m)	9	8	9	8
Total distance (m)	382.9	387.9	1148.6	1163.6

Taking the aforementioned into account, two most informative tests of speed abilities of ice hockey players (both on- and off-ice) are: 1) 5 m sprint; 2) 10 m sprint. The use of a widespread 30 m sprint test is justified in the absence of timing gates, as the accuracy of hand stopwatch linearly decreases with the distance of a test.

The above can be applied to the training process as well. While developing speed qualities, it is justified to place the greatest emphasis on distances up to 11 meters. Distances over 16 meters should be used less often.

The data in Table 3 reflects speeds reached by the KHL players during official games. Maximum sprinting velocities above 9 m/s (32 km/h) are extremely rare in the KHL.

Distance	Forwards per Period	Defencemen per Period	Forwards per Game	Defencemen per Game
3.0 - 3.9 m/sec (10.8 - 14.0 km/h)	1	2	4	6
4.0 - 4.9 m/sec (14.4 - 17.6 km/h)	9	14	27	43
5.0 - 5.9 m/sec (18.0 - 21.2 km/h)	11	15	34	45
6.0 - 6.9 m/sec (21.6 - 24.8 km/h)	10	11	31	33
7.0 - 7.9 m/sec (25.2 - 28.4 km/h)	7	5	21	16
8.0 - 8.9 m/sec (28.8 - 32.0 km/h)	4	2	11	6
9.0 - 9.9 m/sec (32.4 - 35.6 km/h)	1	0	4	1
10.0 - 10.9 m/sec (36.0 - 39.2 km/h)	0	0	1	0

Conclusion

The most informative tests for assessing speed qualities of ice hockey players are 5 and 10 meters sprints. The use of standard 30 meters sprint test, which is so widely used in ice hockey, is justified in the absence of timing gates.

References

1. The Mechanics of Skating / Exploratorium [Online], URL: https://www.exploratorium.edu/hockey/skating2.html (access date: 01.05.2019).
2. Vescovi, J.D. (2012), Sprint speed characteristics of high- level American female soccer players: Female Athletes in Motion Study, Journal of Science in Medicine and Sport, no. 15, pp. 474–478.
3. Gil, S.M., et al. (2007), Selection of young soccer players in terms of anthropometric and physiological factors, Journal of Sports Medicine and Physical Fitness, vol. 47, pp. 25–32.
4. Janot, J.M., Beltz, N.M. and Dalleck, L.D. (2015), Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players, Journal of Sports Science and Medicine, no. 14 (3), pp. 522–529.
5. Reaching top speed in cross-ice hockey. Ontario Minor Hockey Association [Online], URL: https://www.omha.net/ news_article/show/840940 (access date: 01.05.2019).
6. Nikonov, Yu.V. (2014), Physical Training for Hockey, Minsk: Vitposter, 576 p.
7. Haché, A. (2002), The physics of hockey, Baltimore, MD: John Hopkins University Press, 184 p.
8. Buckeridge, E., LeVangie, M.C., Stetter, B., Nigg, S.R. and Nigg, B.M. (2015), An On-Ice Measurment Approach to Analyse the Biomechanics of Ice Hockey Skating, PLoS One, no. 10 (5), e0127324.
9. Henriksson, T., Vescovi, J.D., Fjellman-Wiklund, A. and Gilenstam, K. (2016), Laboratory- and field-based testing as predictor of skating performance in competitive-level female ice hockey, J. Sports Medicine, no. 7, pp. 81– 88.
10. Farlinger, C.M., Kruisselbrink, L.D. and Fowles, J.R. (2007), Relationships to Skating Performance in Competitive Hockey Players, Journal of Strength & Conditioning Association, no. 21 (3), pp. 915–922.
11. Zankavets, U. and Popov, V.P. (2015), Interconnection of Speed, Speed-Strength and Strength Abilities of Professional Hockey Players on Ice and off Ice. Pedagogics, Psychology, Medical-Biological Problems of Physical Training and Sports no. 9, pp. 12–19.
12. Horrigan, J.M. and Kreis, E.J. (2002), Strength, conditioning and injury prevention for hockey; foreword by Luc Robitaille, USA: The McGraw-Hill Companies, 248 p.
13. Matveev, L.P. (1991), Theory and methodology of physical education (general principles of the theory and methods of physical education; theoretical and methodological aspects of sports and professional-applied forms of physical education), Мoscow: Fizkul’tura i sport, 543 p.
14. Jeffreys, I. (Ed.) (2013), Developing Speed, USA: National Strength & Conditioning Association (Sport performance series), 216 p.
15. Baechle, T.R. and Earle R.W. (Eds.), (2008), Essentials of strength training and conditioning. National Strength and Conditioning Association. 3rd ed., Hong Kong: Human Kinetics, 642 p.