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Introduction: Basketball, introduced by Naismith as a contactless and indoor alternative to sports such as American football, now frequently involves physical contact among players, challenging the traditional notion. Up to date, a thorough understanding of these contacts and their implications remains limited. This study aims to analyze player contacts, embedding it within overall load monitoring to optimize performance and reduce injury risk. Methods: Using a mixed-method design, video-based observations and quantitative analysis were employed to study contact characteristics during ten professional male basketball matches. Fisher exact tests and chi-squared tests (p < .05) were conducted to examine positional variations across different contact variables. Results: A total of 2,069 player contacts were examined, showing centers had the most contacts at 40.5%, followed by power forwards (19.6%), point guards (17.7%), shooting guards (12.9%), and small forwards (9.3%). Notably, half-court defense (46.1%) and set offense (48.9%) emerged as the primary game phases associated with the majority of contacts across all playing positions. Key play actions leading to physical contact included screening/picking (25.7%), box outs (22.9%), and fights for position (FFP) (18%). Post hoc analyses identified significant associations between centers (32.6%, 5.93) and point guards (21.5%, -1.98) during screening/picking maneuvers. Moreover, the torso/upper body (48.1%) and upper extremities (38.2%) were identified as the most affected contact points, while lower extremities and the head/neck exhibited minimal impact. Additionally, 81.4% (n = 1,684) of contacts resulted in kinematic displacement, whereas 18.6% (n = 385) exhibited no change. Post hoc analyses indicated significant associations of physical contacts against opposing counterparts for each playing position. Discussion: Basketball entails frequent physical contacts across all playing positions, with distinct patterns observed for each playing position. Integrating contact monitoring alongside traditional load metrics offers a more comprehensive understanding of physical demands in professional basketball. Practical implications include the developing of tailored training strategies based on playing position-specific contact profiles and recognizing the physiological and biomechanical impacts of contacts. Future research should consider whether the number of contacts between players has increased over the years, and it should acknowledge the impact of player contacts on performance in basketball in order to refine training strategies and enhance player well-being.

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This study aimed to determine the distributions of number of shots per point, point duration, point pace and technical actions during the match in professional men and women padel players. A total of 35,145 hits (3239 points; men = 1602 and women = 1637) were analyzed in 20 matches corresponding to quarterfinal, semifinal and final matches of the World Padel Tour 2020 season. The observations were conducted through systematic observation and involved a total of 32 players (16 men and 16 women). Men's points lasted 13.5-14.8 s, comprising 10-11 hits, resulting in a ratio of 0.80 shots per second, with no differences between sets. Women's points lasted longer than men's (14.4 to 16.2 s, p = 0.011) but included a similar number of shots per point, resulting in a lower rhythm of play (0.73-0.75 shots per second, p < 0.001), particularly in the third set (p = 0.004). Volleys, lobs and directs were used in >60% of the points, with a frequency of one to three times per point. Bandejas were used in 50-60% of the points, with a frequency of one to two times per point. Backwalls and flat smashes were used at least once in 30-48% of the points. Selective actions had a greater frequency of use in the third set (i.e., flat smash and smash x3 in women; forehand/backhand volleys and side-wall forehand in men), suggesting occasional changes in the style of play, but likely explained by the onset of fatigue. In conclusion, game volumes, intensity and actions remained broadly similar throughout professional padel matches.

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The objective was to assess and compare the tactical conduct of players aged U-8, U-10, and U-12 during full- and small-sided games, focusing on tactical modeling and interaction dynamics. Each age group comprised three teams (n = 180; 60 per category; 20 per team), engaging in a tournament where teams faced each other once in both formats - 18 matches; 3 per category in each format. Full-sided games (GK + 10 vs.10 + GK; 100 × 68 m) and small-sided games (U-8: GK + 4 vs. 4 + GK (36 × 20 m); U-10: GK + 7 vs. 7 + GK (52.5 × 34 m); U-12: GK + 10 vs. 10 + GK (68 × 45 m). Standard playing times (3 periods of 12 minutes (U-8s); 3 periods of 15 minutes (U-10s); and 3 periods of 20 minutes (U-12s), with a 5-minute break. Variables were examined using descriptive analysis (mean, standard deviation, and confidence interval), with paired t-tests and Wilcoxon tests employed for inter-format comparisons. Despite players benefiting from more time and space in full-sided games (increased ball receptions and overall ball involvement), results from small-sided games indicate three key advantages: 1) More goals (U-8s: z = -3.44, p = .050) and shots on target (U-8: z = -3.25, p = .001; U-10: z = -2.72, p = .007); 2) Game space management-ball circulation in larger amplitude (U-10: t = -4.20, p = .001; U-12: t = -4.35, p < .001); and with more transitions (U-10: t = -3.60, p = .002; U-12: t = -4.16, p = .001) and 3) Fast decision-making-larger ball velocity circulation (U-08: t = -3.54, p = .003; U-10: t = -5.13, p < .001; U-12: t = -5.80, p < .001).

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Introduction: This study investigated the influence of team formation on goal-scoring efficiency through analysing the time required for a goal to be scored in elite football matches. Method: The analysis was conducted using a comprehensive open access dataset encompassing eight major football competitions, including prestigious events such as the World Cup and the UEFA Champions League. It notably focused on the competing risks framework and employed the Fine and Gray model to account for the interplay between two competing events: team A scoring and team B scoring. Results: Through analysis of Team A's goal occurrences, we assessed the offensive capabilities of its formation and the defensive effectiveness of Team B's composition in relation to the time it took for Team A to score a goal. Findings revealed that teams employing the 4-3-3 and 4-2-3-1 formations outperformed other formations (3-4-3, 3-5-2, 4-4-2, 4-5-1, 5-3-2, 5-4-1) regarding goal-scoring efficiency. Discussion: By shedding light on the impact of team formation on goal scoring, this research contributes to a deeper understanding of some of the successful strategic aspects of elite football.

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PURPOSE: our aim was to analyze the characteristics of the off-the-wall smash in men´s and women´s padel, and to compare gender differences in the set-dependent frequency of these shots. STUDY SAMPLE: through systematic observation, we analyzed 441 off-the-wall smashes from the Final Master of the 2022 season of the World Padel Tour. RESULTS: showed that the women performed twice as many off-the-wall smashes as the men. This shot was executed most frequently (90%) from the center and right side of the court and from the dominant side, usually providing volley continuity (73%) and sometimes resulting in point winners (21.5%). Furthermore, there were gender differences, depending on the defense zone from which the wall smashes were defended (p = .014) and on the final match result (p = .018). In men's padel, the losing pair performed more off-the-wall smashes, while in women's padel, the winning pair performed more of these smashes. Finally, between both genders, most off-the-wall smashes occurred in the first set and decreased in number in the third set, with the second set containing the fewest off-the wall smashes.

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PURPOSE: Rugby union is a contact team sport demanding high levels of physical capacity, and understanding the match workloads can be useful to inform training. In this study, the factors influencing locomotion and contact workloads for offensive and defensive ball-in-play periods are quantified. METHODS: Locomotion and contact metrics were collected from global positioning system units and videos for 31 professional players of a Super Rugby team across 14 games in the 2021 season. Data were analyzed with a generalized mixed-model procedure that included effects for type of play, playing position, match outcome, and ball-in-play time. Magnitudes were assessed with standardization, and evidence for substantial magnitudes was derived from sampling uncertainty. RESULTS: When offense was compared to defense, most metrics showed decisively substantial increases (small to moderate) for forwards and backs. There was decisive evidence that locomotion metrics were substantially lower (large differences) and contact metrics were higher (very large differences) when comparing forwards to backs on offense and defense. When winning was compared to losing, there was good evidence that forwards experienced small increases in overall workload on defense, and backs experienced a small increase in high-speed running and a moderate decrease in contacts on offense. Match-to-match changes associated with ball-in-play time, attributed to fatigue, were decisive (moderate to very large) across most metrics for forwards and backs in offense and defense. CONCLUSIONS: The increased locomotion and contact workloads in offensive periods and the differing physical requirements between positions and match outcomes for both types of play are novel findings that should aid practitioners in designing effective training.

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Muscle typology is heterogeneous among national level football (soccer) players, but positional differences remain unclear. Furthermore, fast typology (FT) individuals fatigue more than slow typology (ST) individuals in lab conditions. Therefore, we investigated if muscle typology is different between playing positions and if the decay in high-intensity activities from the first to the second half is larger in FT football players than in ST players. We estimated muscle typology in 147 male professional football players by measuring soleus and gastrocnemius muscle carnosine via proton magnetic resonance spectroscopy. Players were classified as ST, intermediate typology (IT) or FT and categorized as goalkeeper, center back, full back, midfielder, winger or forward. Across four seasons in-game distances covered in multiple running speed, acceleration and deceleration zones were collected during the first and second half. We found no differences in muscle typology between positions (p = 0.412). FT players covered 10.9% more high acceleration distance (>3 m.s-2 ) in the first half than ST players (p = 0.021) and high acceleration distance decay was larger for FT players (-12.4%) than ST (-7.7%; p = 0.006) and IT players (-7.3%; p = 0.010). Moreover, the decline in distance covered in several high-intensity zones tended to be larger in FT players (-11.2% high-intensity >15 km.h-1 ; -12.7% high deceleration <-3 m.s-2 ; -11.5% medium acceleration 2-3 m.s-2 ) than in ST players (-7.1% high-intensity; -8.1% high deceleration; -8.1% medium acceleration; 0.05 < p < 0.1). In conclusion, possessing a particular muscle typology is not required to play any football position at the national level. However, there are indications that FT players might fatigue more toward the end of the game compared to ST players.

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Objective:To study the impact of financial compensation on the competitive strategy selection of public hospitals.Methods:Based on the quality and cost strategy selection framework of public hospitals,the evolutionary game model of strategy selection of secondary and tertiary public hospitals was established,and the influence of different financial compensation methods on the competitive strategy selection of public hospitals was analyzed by matlab simulation.Results:The more public hospitals choose the optimal strategy,the faster they reach the evolutionary stable state of the optimal strategy.The financial compensation of the same unit can change the competitive strategy choice tendency of the secondary hospitals.Regardless of the tertiary or secondary public hospitals,the impact of the compensation quality strategy is greater than the compensation cost policy,but the over-compensation quality strategy will cause the secondary hospitals to deviate from the optimal strategy.The impact of hospital competition costs on secondary public hospitals is much greater than that of tertiary public hospitals.Conclusion:To clarify the positioning and strategy of secondary and tertiary hospitals from the policy;financially increase the investment in the quality construction of tertiary public hospitals and increase the investment in the management level of secondary hospitals;strengthen supervision and management,guide the hospital reasonable competition.

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This research aimed to determine the quantitative and qualitative structure of winning systems of the world's leading male table tennis players between 1970 and 2021. The study used the Wu game analysis method, modified by the authors, which consists of observing the game from playback, identifying the winning actions of a given player, and sorting and counting the actions, depending on the accuracy of the observation. The project identified all World Championships and Olympic Games medallists, resulting in 244 men's matches being analyzed. Three time periods were considered based on the ball used, including the 38 mm celluloid ball, 40 mm celluloid ball, and 40 mm plastic ball. Differences in the level structure, depending on the observation period, were assessed using the chi-squared test of independence. The Pearson contingency coefficient was calculated, and multiple comparisons were made. The research showed that the use of combinations changed slightly with changes in ball size and material. The first three strokes were very important in all periods. However, the importance of serves as direct scoring strokes decreased. These findings may be related to changes in the size and material used for ball production. The most winning serves in the game of the top men were side-spin forehand serves, which were also used most often during 3rd-ball-attack winning combinations. The number of actions won directly with a return, and in the return-counterattack combination, accounted for, and still constitute, about 30%, with an increasing number of backhand flicks. The research also showed an increase in the use of backhand strokes compared to forehand strokes. These findings should be considered when creating basic goals in table tennis training plans.

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The aim of this study is to analyze the worst-case scenarios of professional futsal referees during the first and second half of official matches in the Spanish Futsal Cup using a Local Positioning System (LPS) for monitoring their movement patterns. Eight professional futsal referees (40 ± 3.43 years; 1.80 ± 0.03 m; 72.84 ± 4.01 kg) participated in the study. The external load (total distance, high-speed running distance and efforts, sprint distance and efforts, and accelerations and decelerations distances) of the referees was monitored and collected using an LPS. The results revealed significant differences in the worst-case scenarios of the futsal referees during the match according to the time window analyzed (p < 0.05). The longest time windows (120 s, 180 s, and 300 s) showed lower relative total distances in the worst-case scenarios (p < 0.05). The high-speed running distances were significatively higher in the first half for the 120 s (+2.65 m·min-1; ES: 1.25), 180 s (+1.55 m·min-1; ES: 1.28), and 300 s (+0.95 m·min-1; ES: 1.14) time windows (p < 0.05). No differences were found between the first and second half for the high-intensity deceleration distance (p > 0.05). These results will serve to prepare the referees in the best conditions for the competition and adapt the training plans to the worst-case scenarios.

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Radon is the second leading risk factor for lung cancer after smoking. As a public policy, radon mitigation not only involves radon control technology or its cost-benefit analysis, but also includes the decision-making process of local governments. In this study, the evolutionary game theory was used to analyse the interaction between local governments and residents based on the subsidy of the central government. Considering the practical data in China, factors influencing the behaviour of local governments and residents were discussed using numerical simulations. The results indicated that radon mitigation is a fully government-promoted action; thus, its implementation largely depends on the subsidy of the central government and the share of radon control costs borne by the local government. The financial burden for both local governments and residents is a more important determinant than long-term health effects. The relatively poor local economic situation could limit the implementation of radon control. There would be a public policy paradox wherein cities or regions with higher radon risk would have lower willingness for radon control, mainly due to the significantly higher costs of radon control. This work provides reference data for decision-making to implement radon control and is expected to offer some suggestions for local governments.

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Introduction: Public-private partnership (PPP) older adult care project is an effective means to solve the dilemma of the aging population in China's rural areas, but there are some problems in the operation process, such as a low participation rate and poor service quality, resulting in the needs of rural older adult groups not being met. Methods: To alleviate the pressure of the aging population in rural areas, this study establishes an evolutionary game model for the PPP older adult care project, then defines the interests of local government, the private sector, and rural older adult residents, based on which it discusses the strategic choices of the three parties in the evolutionary process, and finally analyzes the influencing factors of the strategic choices of the game parties through simulation. Results: The results suggest that whether the private sector chooses to actively participate in the project will be influenced by the willingness of local government and rural older adult residents to participate in the project. Local government could play the role of supervisor through reward and punishment mechanisms. Whether older rural residents choose to participate in the project depends on the number of benefits they would receive. Discussion: Based on these findings, local governments should clarify the responsibilities of relevant stakeholders, adopt a regulatory strategy combining subsidies and penalties, improve the participation efficiency of rural older adult residents, promote the effective operation of PPP older adult care projects, and improve the quality of rural older adult care services in the new era.

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Serve and return of the serve are among the most critical technical-tactical factors influencing performance in table tennis (TT). The present study aimed to analyse sex differences in the spatial distribution of serve and serve-return in elite TT players. A total of 48 elite TT players (men: n = 24; women: n = 24) participated in the investigation. A total of 24 matches were recorded and examined, analysing 1,177 plays and 5,319 strokes in the men's competition and 950 games and 5,097 strokes in the women's competition. Technical actions were analysed using an observation tool validated by two expert TT coach with a high level of agreement (K > 0.80). Men distributed their serves over zones 1 and 2 of the table, while women more frequently selected zone 5 (p < 0.05). In men, 30.1% of the serves were near the net, 63.6% in the middle zone of the table and 6.2% in the end zone of the table, while in women, these values were 10.9%, 67.2%, and 21.8%, respectively. As for the technique of the serve-return depending on the zone of the service, in men the action of the cut from zone 1 and 2 predominated, while in women this technique was more frequent from zone 5 (p < 0.05). On the other hand, the serve-return with the flip technique in zone 1, 3 and 4 was more frequent in men (p < 0.05). As for the return of the serve with the topspin technique, there were differences in zone 3, being more frequent in men (p < 0.05). Finally, the serve return with cut and defensive serve-return techniques in zones 3, 4, 5, and 6 were more frequent in women (p < 0.05). There are differences between sexes in service and return of serve actions during a match in elite players.

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The objective of this research was to analyze the importance of maintaining the net position in men's and women's professional padel. The data sample was drawn from 2,756 padel rallies (n = 1,434 men's and n = 1,322 women's) in matches played during the 2021 season of the World Padel Tour circuit. The results showed that there was no net exchange in 50.7% of the women's rallies, while in 65.9% of men's rallies, the servers kept the net. Due to their physical advantages, men servers had more opportunities to finish the rally at the net than women servers, giving them more opportunities to win the rally. However, when either men or women receivers finished the rally at the net, they had more opportunities to win the rally. In addition, both men and women tended to end the rallies with a winner when they were in the net zone and with an error when they were at the back of the court. These findings suggest that wins in padel are closely related to time spent at the net.

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How to ensure the smooth implementation of convergent infrastructure engineering as the risk of sudden public events persists, allowing the engineering supply chain companies to break through the blockages to regenerate collaboratively and form a regenerated collaborative union. By establishing a mathematical game model, this paper explores the synergistic mechanism of supply chain regeneration for convergent infrastructure engineering, which takes into account cooperation and competition, investigates the impact of supply chain nodes' regeneration capacity and economic performance, as well as the dynamic changes in the importance weights of supply chain nodes, when adopting the collaborative decision of supply chain regeneration, the benefits of the supply chain system, are more than those when suppliers and manufacturers "act of one's own free will" by making decentralized decisions to undertake supply chain regeneration separately. All the investment costs of supply chain regeneration are higher than those in non-cooperative games. Based on the comparison of equilibrium solutions, it was found that exploring the collaborative mechanism of its convergence infrastructure engineering supply chain regeneration provides useful arguments for the emergency re-engineering of the engineering supply chain with a tube mathematical basis. Through constructing a dynamic game model for the exploration of the supply chain regeneration synergy mechanism, this paper provides methods and support for the emergency synergy among subjects of infrastructure construction projects, especially in improving the mobilization effectiveness of the entire infrastructure construction supply chain in critical emergencies and enhancing the emergency re-engineering capability of the supply chain.

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This study aimed to analyse physical performance relative to peak locomotor demands of match play. Data were collected during 13 professional soccer matches. Initially, the 1-minute peak values were registered in each match, including the percentage of the total distance (TD), high-speed running distance (HSRD), sprinting distance (SPD), and high-metabolic load distance (HMLD), and a total of high-intensity accelerations and decelerations (Acc+Dec). Secondly, the time (measured in minutes) spent at different percentage ranges for the 1-minute peak values registered in each match was calculated. Thirdly, the physical performance required in the different percentage ranges for the 1-minute peak values were obtained. Finally, the time and physical performance required above the 90-minute average demands were calculated. The 90-minute average for all playing positions represented ~53% of the total distance (TD), ~23.4% of high-metabolic load distance (HMLD), ~16% of high-speed running distance (HSRD), ~11% of the total of high-intensity accelerations and decelerations (Acc+Dec), and ~6% of sprinting distance (SPD) for the 1-minute peak values. Likewise, statistically significant differences (p < 0.05) in the physical performance and time spent between specific percentage ranges for the 1-minute peak locomotor demands were also noted. In addition, all the variables reported that the physical performance required for above 90-minute average demands were significantly greater (p < 0.05) than the 90-minute average demands. Therefore, these findings may guide the prescription of training intensity by considering the physical performance relative to the peak locomotor demands of match play.

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This study analysed the periods in which the most demanding passages (MDP) of play occurred during professional soccer matches, considering different criterion variables and investigating the effect that the playing position had on the MDP-of-play occurrence for each criterion variable. The MDP of play were calculated based on five criterion variables: distance covered (DIS), sprinting distance (SPD), high-metabolic load distance (HMLD), and the total of high-intensity accelerations and decelerations (ACCHIGH and DECHIGH). The results showed that the first period of the match (0'-15') was the interval with the highest frequency (i.e., the greatest % of cases) in which the players achieved the MDP of play for all the variables (DIS= 38.9%; SPD= 28.4%; HMLD= 37.7%; ACCHIGH= 54.3%; DECHIGH= 48.8%). The playing position had no significant effect on MDP-of-play occurrence in any variable (likelihood ratio, LR= 15.88-32.05; p > 0.05; effect size, ES= 0.01-0.04), except for the DIS covered (LR= 32.05; p= 0.04; ES= 0.05), in which the most frequent MDP for the full backs occurred within the second period of the match (15'-30'). In conclusion, the first periods of the matches usually elicited the MDP of play and these periods need to be trained to prevent injuries and optimize performance.

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The aims of this study were to 1) determine the key load indicators in professional soccer through principal component analysis (PCA); and 2) analyse the load variability of each training and match day within the microcycle considering the principal components. Data from 111 load variables were collected using tracking systems in both training and match days (MD). The results showed that 7 variables, which belonged to the first two components of the PCA, explained 80.3% of total variance. Specifically, these variables were Metabolic power, total of steps, Fourier transform (FFT) duration, deceleration distance covered (2-3 m/s2), total of running actions (12-18 km/h; 21-24 km/h), and distance covered (6-12 km/h). Regarding the analysis of the load variability of each training and match day within the microcycle, the lowest load variability was observed in -1MD. Also, a great load variability in +1MD with significant differences compared to -5MD (p<0.001; d=0.49) and -4MD (p=0.01; d=0.26) was found. This study suggests the use of the PCA in the context of team sports to reduce the large number of variables, which are daily managed by strength and conditioning coaches, in addition to the analysis of load variability of each training and match day within the microcycle.

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The aims of this study were to examine the periods in which the maximum speed actions occurred during elite soccer matches and analyse these actions considering the effect of playing position and different contextual variables. Performance-related variables (VMAX: maximum speed; Vo: starting speed; SPD: sprinting distance; ACCMAX: maximum acceleration; DECMAX: maximum deceleration) and sprint-related contextual variables (trajectory, ball possession, role, field area in which the action occurred) from each maximum speed action were collected. The first 15 minutes of each match half elicited most maximum speed actions (44.6% of cases), regardless of playing position (likelihood ratio, LR=13.95; p=0.95). However, playing position had a significant effect on the role of the action (Chi-Squared, χ2=50.68; p=0.001) and the field area in which the sprint occurred (χ2=26.54; p=0.001). Regarding the effect of different contextual variables on the sprint-related performance variables, no significant effect from any contextual variable on ACCMAX, DECMAX or Vo was found (p > 0.05). Nevertheless, the contextual variables had a significant effect on SPD (from ball possession: sprints without ball > sprints with ball; trajectory: non-linear sprints > linear sprints; role: offensive sprints > defensive sprints) and VMAX (from ball possession: sprints without ball > sprints with ball; playing position: midfielders < other positions).

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Relative metrics (i.e. distance covered per minute of match time) are regularly used to quantify soccer player movement demands. However, limited literature is available concerning the peak player demands during training. This study aimed to compare the relative and peak demands of conditioning-focused various-sided training games (VSG) to competition matches in elite youth male soccer players according to playing position. Data from twenty-nine competition matches (national) and twenty-two VSGs (small, medium, and large) were collected for twenty-three elite under-17 soccer players using 15-Hz portable global positioning system tracking devices (GPSports, Canberra, Australia). Relative player movements were reported as total distance (TD) and high-speed running distance (HSRD) (> 5.0 m/s) per minute of total playing time. Peak player movements were calculated using a 1-minute rolling epoch length, reported as the maximum TD and HSRD. Linear mixed models demonstrated interactions between VSG type and player position for relative TD (p < 0.001) and HSRD (p < 0.001), and peak TD (p = 0.010) and HSRD (p = 0.003). The relative TD of VSGs were greater than match-play for all player positions. However, only Central Defenders demonstrated similar HSRD in MSGs and LSGs compared to match-play when analysed using relative calculations. External Attackers also replicated match-play relative HSRD demands in LSGs. No VSG type was found to replicate or supersede the peak player movements of match-play across any playing position. Consequently, VSGs should be supplemented with high-speed running training to prepare players for the peak running requirements of match-play.