On-Ice and Off-Ice Fitness Profiles of Elite and U20 Male Ice Hockey Players of Two Different National Standards

This is a self-archived version of an original article. This version may differ from the original in pagination and typographic details. Author(s): Title: Year: Version: Copyright: Rights: Rights url: Please cite the original version: CC BY-NC-ND 4.0 https://creativecommons.org/licenses/by-nc-nd/4.0/ On-Ice and Off-Ice Fitness Profiles of Elite and U20 Male Ice Hockey Players of Two Different National Standards © 2020 by the National Strength & Conditioning Association. Accepted version (Final draft) Vigh-Larsen, Jeppe F.; Haverinen, Marko T.; Panduro, Jeppe; Ermidis, Georgios; Andersen, Thomas B.; Overgaard, Kristian; Krustrup, Peter; Parkkari, Jari; Avela, Janne; Kyröläinen, Heikki; Mohr, Magni Vigh-Larsen, J. F., Haverinen, M. T., Panduro, J., Ermidis, G., Andersen, T. B., Overgaard, K., Krustrup, P., Parkkari, J., Avela, J., Kyröläinen, H., & Mohr, M. (2020). On-Ice and Off-Ice Fitness Profiles of Elite and U20 Male Ice Hockey Players of Two Different National Standards. Journal of Strength and Conditioning Research, 34(12), 3369-3376. https://doi.org/10.1519/jsc.0000000000003836 2020 1 On-ice and off-ice fitness profiles of elite and U20 male ice hockey players of two different national standards Jeppe F. Vigh-Larsen1, Marko T. Haverinen2,3, Jeppe Panduro4, Georgios Ermidis4,5, Thomas B. Andersen1, Kristian Overgaard1, Peter Krustrup4,6,7, Jari Parkkari8, Janne Avela2,9, Heikki Kyröläinen2,9, and Magni Mohr4,10 1Section for Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark; 2Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland; 3Varala Sports Institute, Tampere, Finland; 4Department of Sports Science and Clinical Biomechanics, SDU Sport and Health Sciences Cluster (SHSC), Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark; 5Department of Movement Sciences and Wellness, “Parthenope” University of Naples, Naples, Italy; 6Shanghai University of Sport (SUS), Shanghai, China, 7Sport and Health Sciences, University of Exeter, Exeter, United Kingdom; 8Tampere Research Center of Sport Medicine, UKK Institute, Tampere, Finland; 9Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland; 10Centre of Health Science, Faculty of Health Sciences, University of the Faroe Islands, Tórshavn, Faroe Islands. Submission type: Original investigation Running head: Fitness characteristics in elite male ice hockey Correspondence to: Professor, Magni Mohr Department of Sports Science and Clinical Biomechanics Sport and Health Sciences Cluster (SHSC) University of Southern Denmark, 5250 Odense M, Denmark Tel.: +298 292270 e-mail: [email protected] 2 Abstract Differences in body composition and performance were investigated between elite and U20 male ice hockey players of two different national standards. 179 players were recruited from the highest Finnish (n=82) and Danish (n=61) national level. In addition, one U20 team from Finland (n=19) and Denmark (n=17) participated. Body composition and countermovement jump performance (CMJ) were measured off-ice in addition to on-ice assessments of agility, 10 and 30-m sprint performance and endurance capacity (the maximal Yo-Yo Intermittent Recovery Level 1 Ice Hockey Test, Yo-Yo IR1-IHmax). Large differences in on-ice performances were demonstrated between Finnish and Danish elite players for agility, 10 and 30-m sprint performance (2-3%, P≤0.05) and Yo-Yo-IR1-IHmax performance (15%, P≤0.05). In contrast, no differences (P>0.05) were present between elite players for CMJ ability or body composition. However, elite players possessed more body and muscle mass than U20 players. Finally, the Finnish U20 cohort had a similar performance level as the Danish elite players and superior 10-m sprint performance, whereas the Danish U20 level was inferior to the other groups in every performance assessment (P≤0.05). In conclusion, on-ice speed and endurance differ markedly between elite players of two national standards with no difference in body composition or CMJ ability. Moreover, the most consistent difference between U20 and senior elite players was related to body and muscle mass. These results highlight the usefulness of on-ice assessments and suggests the importance of on-ice high-intensity training in elite players in addition to training targeted the development of lean body mass in youth prospects. Keywords: Level of competition, intermittent exercise performance, team sport, sprinting, agility. 3 INTRODUCTION Elite ice hockey is a unique team sport due to the intense intermittent activity pattern, including repeated bouts of fast-paced skating in intervals often ranging from 30 to 60 s, interspersed by longer duration of passive recovery (~2-5 min) (7, 19, 21). Effective playing time normally ranges from 15 to 25 min with some individual players exposed to significantly more or less time on the ice (7, 19, 21). The skating pattern in ice hockey has been demonstrated to be highly demanding for both aerobic and anaerobic energy pathways (7, 21). For example, we recently demonstrated that peak muscle lactate and phosphocreatine values during an elite game were higher and lower, respectively, than observed during a soccer game (36), indicative of a large anaerobic contribution to the energy turnover. This metabolic response resulted in a markedly high glycogen degradation with almost 65% of individual fast and slow-twitch fibers being nearly emptied of glycogen following the game (36). In concert, average on-ice heart rate was ~85% of maximum values with peak values approaching maximal levels, demonstrating an additionally elevated cardiorespiratory loading. Thus, ice hockey players require a broad range of physical qualities in order to compete at the elite competitive level, including aerobic and anaerobic capabilities as well as strength and size for physical encounters. Recently, we demonstrated large differences in body composition and on-ice measurements of endurance and high intensity performance between elite and sub-elite male ice hockey players, in a large sample-size study, suggesting that several fitness components are important at the elite level (35). These results are largely in accordance with previous findings in smaller sample-size studies comparing players of different competitive standards (3, 25, 30, 31). However, discrepancy exists with regards to aerobic capacity since some studies fail to report any differences between level of play, when assessed in a laboratory setting, contrasting our previous findings using on-ice assessments (13, 25, 32, 35). Thus, it has been demonstrated that maximal oxygen uptake and lactate threshold values vary markedly between cycling and skating based assessments, possibly due to different biomechanical requirements (8). In addition, no differences in VO2max values have been demonstrated in soccer players across competitive levels, in contrast to large differences in specific intermittent running test performances (17, 33). Therefore, specific on-ice tests may be more valid and sensitive tests to detect differences in on-ice performance. However, no study has yet elucidated whether disparities in fitness components are present, even at the elite level when comparing two different national standards by the application of specific on-ice test procedures. Exploring this phenomenon is valuable for identifying important key performance indicators, for tailoring specific fitness regimens and for obtaining knowledge informing talent selection criteria. Thus, 4 it may be hypothesized that, in two top-level national standards, all players will be characterized by a very high fitness level and potential differences therefore will be marginal. On the other hand, certain critical fitness components may still be important factors distinguishing between players of different national standards including diverse cultural sport settings, training approaches and international world ranking. The principal objective of the present investigation was therefore to compare fitness profiles and body composition in elite players of two national standards in a large sample of players, applying specific on-ice and off-ice test procedures. A secondary aim was to compare the fitness level of players of these elite standards with U20 players from both countries to test for potential age-related differences. Finally, differences between specific positional roles were examined. Based on previous findings in elite and sub-elite players we hypothesized that elite players would substantially outperform U20 players in both endurance and high-intensity performance assessments, while variability between national elite standards would be small, but in favor of the top-ranked national level. METHODS Experimental Approach to the Problem The study is based on data collected from teams from the highest Finnish and Danish ice hockey divisions as well as at U20 level in both countries during the pre-season period. The Danish and Finnish highest national standards differ in international ranking as the Finnish teams currently are awarded five spots – the maximum number – in the highest international competition, The Champions Hockey League, whereas the Danish teams are awarded only one spot, based on previous international success. Moreover, Finland is currently ranked 3rd in the International Ice Hockey Federation world ranking for national teams, whereas Denmark is ranked 12th, which may be an indirect reflection of the level of play in the respective national leagues. The teams included were tested in a randomized order after allowing for a minimum of 1 week of familiarization with skating movements following the summer break. We evaluated body composition and performance differences between elite and U20 players from both countries representing various positions applying a simple field-test battery consisting of off-ice and on-ice tests. The players refrained from practice games or heavy exercise for 24 hours prior to testing. Moreover, all players were instructed to follow their habitual diet leading up to training and games, and to avoid alcohol and tobacco for 12 hours prior to testing. All testing procedures were performed in the morning around 10-12 a.m. Exclusion criteria were 5 injuries leading to absence from training for more than 3 days in the 3 weeks preceding the testing sessions. Subjects In total, 179 competitive male ice hockey players were recruited. 143 players (17-38 years) from three Finnish (n=82) and three Danish elite teams (n=61) competing in their respective top national leagues participated in the study comprising: 79 forwards, 50 defensemen and 14 goaltenders (goaltenders were only included in the positional analyses). Additionally, the remaining 36 players were U20 players (16-20 years) recruited from one Finnish U20 team (n=19) and one Danish U20 team (n=17). These comprised: 25 forwards and 11 defensemen, whereas no goaltenders from this level of play were included since no analyses of positional differences at the U20 level were performed. All players were informed of the potential risks and benefits of their participation in the data collection. The study was conducted in accordance with the Declaration of Helsinki and approved by the local ethics committee in each country, and all players (or parents if players were below 18 years of age) gave their written informed consent to participate. Procedures Test procedures were completed for each team within a single test-session consisting of off-ice tests followed immediately by on-ice tests in a standardized order. Off-ice testing. Off-ice tests comprised body composition measured on a bio-impedance scanner (InBody 270, InBody, USA, California), height measurements (Tanita Leicester Height Measurer, Invicta Plastics Limited, Leicester, United Kingdom) and countermovement jump (CMJ) performance (Swift Performance jump mat, Swift Performance Equipment, Australia). A 5-min standardized warm-up consisting of body weight exercises (airsquats and lunges) was performed followed by 4-5 familiarization jumps before testing. Three maximal attempts were allowed interspersed by a 1-min recovery period, as previously described (28). Countermovement jumps were performed with arms fixed at the hip and without bending the knees during the flight or landing phase before contact with the mat, strictly supervised by the test leaders. The reliability of the countermovement jump tests has previously been assessed demonstrating a high reliability with an intraclass correlation coefficient of 0.98 (20). For InBody measurements strong correlation coefficients have previously been demonstrated for 6 body fat percentage (>0.95) and muscle mass (>0.78) between these devices and Dual-Energy X-ray absorptiometry scans which is considered the golden standard test (15). On-ice testing. On-ice tests were performed in full hockey gear with stick in hand. These included the 5-10-5 Pro Agility test, a 10 and 30 m linear sprint test and the maximal Yo-Yo Intermittent Recovery Ice Hockey Test (Yo-Yo IR1-IHMAX). A standardized warm-up was performed on-ice prior to testing including ~10 min of sub-maximal skating at increasing intensity followed by specific warm-up prior to each test as described below. Agility performance was measured using the on-ice 5-10-5 Pro Agility test as previously described (14, 35). Three cones were positioned separated by 5 m and the players positioned at the middle cone facing forward next to a starting gate (Witty Gate Wireless Training Timer Photocells, Microgate with a precision of 0.001 s). A dual beam setup was used to prevent interference from swinging limbs or the stick accidently activating the timers prematurely. The test was initiated by the players accelerating either left or right (in the order right, left and optional during the three attempts recorded), making a cutting turn at the next line before accelerating back through the start gate to the opposite line and back to the starting line again. The players had to turn on the right leg when going right and the left leg when going left to ensure that both legs were utilized as outer legs during the maneuvers. The players were familiarized and warmed up by 2-3 self-paced attempts before the maximal test. The players had 2 min of recovery between each attempt which was supervised by experienced test personnel. Attempts were discarded if the players turned early or did not turn on the proper leg. The fastest agility time was obtained and included in the analysis. The reliability of the test has previously been demonstrated to be high with an intraclass correlation coefficient of 0.82 (23) Linear sprint ability was measured using 10and 30-m split times, with the players starting from a standing position 1 m behind the first timing gates. The same timing system was used as during the agility test, ensuring a high level of precision. 2-3 self-paced warm-up and familiarization attempts were performed before the two maximal attempts separated by 2 min of recovery. The fastest time for 30 m was recorded and used in the analysis together with the 10-m split time from that same attempt. An intraclass correlation coefficient of 0.92 has previously been reported for this test demonstrating a high reliability (12). Subsequently, the players performed the Yo-Yo IR1-IHMAX as previously described (35). Thus, players skated intermittently back and forth between two lines separated by 20 m at increasing speeds until exhaustion. The players were allowed one warning the first time they 7 failed to keep up with the pace of the test before being withdrawn after the second warning. The total distance covered after the withdrawal from the test was recorded as the final score. The players were given strong verbal encouragement to provide a maximal effort. Ice-lanes were changed mid-way through the test after level 17.1 in order to maintain optimal ice conditions. The reliability of the Yo-Yo IR1-IHmax has previously been reported for other team sports with a coefficient of variance of 4.9% (16). Statistical analyses Data are presented as mean ± SD. Data normality was checked using a Shapiro-Wilk test. Differences between level of play and positional roles were assessed using a one-way analysis of variance (one-way ANOVA). Goaltenders were excluded of the overall analyses of differences between level of play and only included in the positional analyses at the elite level. When a significant interaction was found, multiple comparison procedures were applied using the Holm-Sidak method to detect where a significant difference existed. For comparisons between positional roles, only elite players were included due to the lower number of players in the U20 sample. Effect size measures were calculated for differences between groups. Correlations were calculated between anthropometric variables and performance measures as well as between test performances using a Pearson Product Moment Correlation only within the Danish and Finnish total pool of elite players. Correlation coefficients were interpreted in accordance with guidelines by Cohen (6) as small (r = 0.10-0.29), medium/moderate (r = 0.300.49) or large (r ≥ 0.5), while effect sizes were also interpreted as small (d = 0.20-0.49), medium (d = 0.50-0.79) or large (d ≥ 0.80). Significance was accepted at p ≤ 0.05. All statistical analyses were performed using the statistical software SigmaPlot (SigmaPlot for Windows version 14.0, Systat Software Inc., London, United Kingdom). RESULTS Body composition Differences in body composition are shown in Table 1 and Figure 1. There were no differences in height between any groups, while the elite players of both Finland and Denmark were 713% heavier than their U20 counterparts (P≤0.05, ES=0.7-1.3). There were no differences in body fat content, while muscle mass was 13-16% higher in the elite players of Denmark and Finland compared to Danish U20 players (P≤0.05, ES=1.2 and 1.5). In addition, Finnish elite players possessed 9% more muscle mass than Finnish U20 players (P≤0.05, ES=0.9) 8 *** Table 1 around here *** *** Figure 1 around here *** Off-ice and on-ice performance Differences in off-ice and on-ice performance are shown in Table 1 and Figure 2. No difference was apparent in CMJ height between Finnish and Danish elite players, while there was also no difference between these elite groups and Finnish U20 players. Instead, all three groups jumped higher (7-14%) than Danish U20 players (P≤0.05, ES=0.8-1.5). In the on-ice 5-10-5 Pro Agility Test, Finnish elite players performed 2% better than the Danish elite players (P≤0.05, ES=1.1), while all groups performed 4-7% better than the Danish U20 players (P≤0.05, ES=1.5-2.8). In the 10-m linear sprint test, Finnish elite and U20 players performed 2-3% better than Danish elite players (P≤0.05, ES=0.5-0.8). Unfortunately, results for this particular test were not obtained for Danish U20 players for comparison. In the 30-m sprint test, all groups performed 6-7% better than Danish U20 players (P≤0.05, ES=1.3-2.9), while Finnish elite players performed 3% better than Danish elite players (P≤0.05, ES=1.1) In addition, the Yo-Yo-IR1IHmax distance covered was 40-55% greater in all groups compared with Danish U20 players (P≤0.05, ES=1.7-2.6). Finally, Finnish elite covered 15 and 11% more distance (P≤0.05, ES=0.8-1.0) than Danish elite and Finnish U20 players, respectively, while no difference was apparent between the latter two groups. *** Figure 2 around here *** Positional differences Positional differences were assessed within the elite level in Finland and Denmark independently (see Table 2 and Figure 2). There were no significant differences between forwards and defensemen in either country, nor between goaltenders, defensemen and forwards for the off-ice and body compositional tests, in which these were compared. *** Table 2 around here *** Relationships between body composition and performance There were small correlations between height, body mass and 10-m sprint performance (r=0.21 and 0.29, P≤0.05). In addition, height correlated weakly with 30-m sprint performance (r=0.20, 15 27. Rampinini E, Sassi A, Azzalin A, Castagna C, Menaspa P, Carlomagno D, et al. Physiological determinants of Yo-Yo intermittent recovery tests in male soccer players. Eur J Appl Physiol 108: 401-409, 2010. 28. Ransdell LB, Murray TM, and Gao Y. Off-ice fitness of elite female ice hockey players by team success, age, and player position. J Strength Cond Res 27: 875-884, 2013. 29. Robbins SM, Renaud PJ, and Pearsall DJ. Principal component analysis identifies differences in ice hockey skating stride between highand low-calibre players. Sports Biomech: 1-19, 2018. 30. Roczniok R, Stanula A, Gabrys T, Szmatlan-Gabrys U, Golas A, and Stastny P. Physical fitness and performance of polish ice-hockey players competing at different sports levels. J Hum Kinet 51: 201-208, 2016. 31. Roczniok R, Stanula A, Maszczyk A, Mostowik A, Kowalczyk M, Fidos-Czuba O, et al. Physiological, physical and on-ice performance criteria for selection of elite ice hockey teams. Biol Sport 33: 43-48, 2016. 32. Smith DJ, Quinney HA, Steadward RD, Wenger HA, and Sexsmith JR. Physiological profiles of the Canadian Olympic Hockey Team (1980). Can J Appl Sport Sci 7: 142146, 1982. 33. Tonnessen E, Hem E, Leirstein S, Haugen T, and Seiler S. Maximal aerobic power characteristics of male professional soccer players, 1989-2012. Int J Sports Physiol Perform 8: 323-329, 2013. 34. Vescovi JD, Murray TM, and Vanheest JL. Positional performance profiling of elite ice hockey players. Int J Sports Physiol Perform 1: 84-94, 2006. 35. Vigh-Larsen JF, Beck JH, Daasbjerg A, Knudsen CB, Kvorning T, Overgaard K, et a.. Fitness Characteristics of Elite and Subelite Male Ice Hockey Players: A CrossSectional Study. J Strength Cond Res 33: 2352-2360, 2019. 36. Vigh-Larsen JF, Ermidis G, Rago V, Randers MB, Fransson D, Nielsen JL, et al. Muscle metabolism and fatigue during simulated ice hockey match-play in elite players. Med Sci Sports Exerc, 2020. Publish ahead of print. Legends to figures Figure 1. Differences in body composition among Finnish elite and U20 and Danish elite and U20 players for A) height, B) weight, C) body fat percentage and D) muscle mass. Data are presented as mean and individual values. Figure 2. Differences in performance among Finnish elite and U20 and Danish elite and U20 players for E) countermovement jump, F) agility, G) 30-m sprint and H) Yo-Yo IR1-IHmax performance. Data are presented as mean and individual values. 16 Tables 17 Table 1. Age, body composition and performance of elite and U20 male ice hockey players from the highest Finnish and Danish level of play Finnish elite (n=74) Danish elite (n=55) Finnish U20 (n=19) Danish U20 (n=17) Effect size Age (yrs.) 25.9±5.4 (24.7-27.2)§& 23.9±4.5 (22.7-25.1)§& 18.7±0.9 (18.3-19.2)*# 18.1±1.7 (17.2-18.9)*# 0.4, NS, 1.6, 1.5, 1.3, 1.4 Height (cm) 183.0±6.4 (181.5-184.5) 182.3±6.0 (180.7-183.9) 180.0±7.2 (176.5-183.4) 179.0±5.9 (176.0-182.1) NS Body mass (kg) 86.1±7.8 (84.3-87.9)§& 84.3±8.3 (82.0-86.5)§& 78.6±8.4 (74.5-82.6)*# 75.7±10.1 (70.5-80.9)*# NS, NS, 1.3, 1.0, 0.7, 1.0 Body fat (%) 12.6±3.1 (11.9-13.4) 13.3±3.2 (12.4-14.2) 13.8±3.2 (12.2-15.3) 13.4±4.6 (11.0-15.9) NS Muscle (kg) 43.5±4.6 (44-44.6)§& 42.0±4.4 (40.8-43.2)& 39.4±4.5 (37.2-41.5)* 36.5±4.7 (34.1-38.8)*# NS, NS, 1.5, 0.9, NS, 1.2 CMJ (cm) 45.1±4.2 (44.0-46.1)& 43.3±4.1 (42.1-44.4)& 42.7±4.9 (40.3-45.1)& 39.0±3.9 (37.0-41.0)*#§ 0.4, 0.8, 1.47, 0.5, NS, 1.1 Agility (s) 4.68±0.09 (4.66-4.70)#& 4.79±0.12 (4.76-4.83)*& 4.74±0.16 (4.66-4.82)& 5.01±0.19 (4.91-5.10)*#§ 1.1, 1.5, 2.8, NS, NS, 1.5 Sprint 10-m (s) 1.71±0.04 (1.70-1.72)# 1.77±0.10 (1.74-1.79)*§ 1.72±0.06 (1.69-1.74)# N/A 0.8, N/A, N/A, NS, 0.5, N/A Sprint 30-m (s) 4.06±0.09 (4.04-4.08)#& 4.19±0.14 (4.15-4.22)*& 4.12±0.12 (4.06-4.18)& 4.38±0.16 (4.30-4.46)*#§ 1.1, 1.8, 2.9, 0.6, 0.5, 1.3 Yo-Yo IR1-IH (m) 2880±392 (2783-2977)#§& 2505±383 (2396-2613)*& 2600±248 (2476-2723)*& 1862±358 (1677-2045)*#§ 1.0, 2.4, 2.6, 0.8, NS, 1.7 Data are presented as mean ± SD and 95% confidence intervals. Total numbers of players are compared between elite and U20 level of play in both countries while positional differences are analyzed only at the elite level of play within each country. Goaltenders are excluded from these comparisons. * = significant difference from Finnish elite players; # = significant difference from Danish elite players; § significant difference from Finnish U20 players; & = significant difference from Danish U20 players, P≤ 0.05. Effect sizes are presented in the order Finnish elite vs Danish elite, Finnish U20 vs Danish U20, Finnish elite vs Danish U20, Finnish elite vs Finnish U20, Danish elite vs Finnish U20 and Danish elite vs Danish U20. NS = non-significant. N/A = not applicable. 18 Table 2. Positional differences in age, body composition and performance in players from the highest Finnish and Danish level of play Finnish elite players Danish elite players Forwards (n=46) Defensemen (n=28) Goaltenders (n=8) Forwards (n=33) Defensemen (n=22) Goaltenders (n=6) Age (yrs.) 25.8±5.4 (24.0-27.3) 26.2±5.7 (24.2-28.1) 23.8±4.0 (19.4-29.7) 23.8±4.0 (22.5-26.1) 24.0±5.3 (21.8-25.0) 23.5±5.1 (17.5-28.5) Height (cm) 182.2±6.6 (180.3-184.2) 184.2±6.1 (181.8-186.5) 189.1±5.2 (184.8-193.5) 182.1±6.4 (179.8-184.4) 182.5±5.4 (180.1-184.9) 185.2±7.8 (177.0-193.3) Body mass (kg) 86.1±8.4 (83.6-88.6) 86.2±6.8 (83.6-88.9) 86.5±6.9 (80.8-92.2) 84.1±7.8 (81.3-86.9) 84.5±9.0 (80.5-88.5) 82.6±6.1 (76.3-89.0) Body fat (%) 13.0±3.0 (12.1-14.0) 11.9±3.2 (10.6-13.2) 11.9±4.4 (8.1-15.6) 13.3±3.0 (12.2-14.3) 13.3±3.6 (11.7-14.9) 13.2±4.2 (8.8-17.6) Muscle (kg) 43.1±4.7 (41.6-44.6) 44.2±4.4 (42.3-46.0) 43.7±3.2 (38.9-43.9) 42.0±4.9 (40.2-43.7) 42.0±3.7 (40.4-43.6) 41.1±3.6 (37.3-44.8) CMJ (cm) 44.5±4.3 (43.1-45.9) 46.2±3.8 (44.4-48.0) 40.8±5.2 (35.9-45.6) 43.4±3.7 (42.0-44.7) 43.1±4.7 (41.0-45.3) 43.7±5.2 (37.3-50.2) Agility (s) 4.67±0.09 (4.64-4.70) 4.71±0.14 (4.65-4.72) N/A 4.77±0.13 (4.72-4.81) 4.83±0.10 (4.79-4.88) N/A Sprint 10-m (s) 1.71±0.04 (1.69-1.72) 1.71±0.05 (1.69-1.73) N/A 1.77±0.10 (1.73-1.81) 1.76±0.11 (4.79-4.88) N/A Sprint 30-m (s) 4.05±0.09 (4.02-4.08) 4.07±0.10 (4.03-4.11) N/A 4.19±0.13 (4.14-4.23) 4.18±0.15 (4.12-4.25) N/A Yo-Yo IR1-IH (m) 2933±402 (2803-3063) 2800±369 (2651-2949) N/A 2534±396 (2387-2682) 2460±367 (2288-2631) N/A Data are presented as mean ± SD and 95% confidence intervals. Positional differences are compared within elite players of each independent country only. No significant differences between positions were present (P≥0.05). N/A = not applicable. 19 Figures Fig 1. 20 Fig 2.