Central Midfielders Research Articles

Within- and between-mesocycle variations of well-being measures in top elite male soccer players: a longitudinal study

Background: The aims of this study were to describe the variations of training monotony (TM), training strain (TS), and acute:chronic workload ratio (ACWR) through Hooper Index categories (fatigue, stress, DOMS, and sleep quality) and to compare those variations between player status and player positions. Methods: Seventeen male professional soccer players participated in this study. Considering player status, participants were divided in nine starters and eight non-starters. Additionally, participants were divided by playing positions: three wide defenders, four central defenders, three wide midfielders, four central midfielders, and three strikers. They were followed during 40-week in-season period. TM, TS, and ACWR were calculated for each HI category, respectively. Data were grouped in 10 mesocycles for further analysis. Results: Results showed variations across the mesocycles. In general, starters showed higher values for TM, TS, and ACWR calculations than non-starters, although there were some exceptions. Regarding player positions, significant differences were found in stress between wide defenders vs central midfielders for TM (p = 0.033, ES = 5.16), central defenders vs wide defenders for ACWR (p = 0.044, ES = 4.95), and in sleep between wide defenders and strikers for TM (p = 0.015, ES = 5.80). Conclusions: This study revealed that an analysis of players’ well-being parameters according to player status and positions can provide clear information to the coaches and their staff to complement the tasks of training monitoring.

Changes of physical match performance after the COVID-19 lockdown in professional soccer players according to their playing position.

The aim of this study was to evaluate the impact of the pandemic lockdown, which included training cessation and home-based training, on physical performance in professional soccer players from the Polish Ekstraklasa according to their playing position. The research was based on 3137 players’ individual match performance observations during the 2019/2020 season divided into before (26 matchdays) and after (11 matchdays) lockdown periods. The data were collected using the computerised multiple-camera optical tracking system TRACAB (ChryronHego VID, New York, NY) with a sampling frequency of 25 Hz. Independently of playing position, a significant (p < 0.001) reduction in season resumption metrics of total distance (-0.9%), jogging (-1.6%), running (-3.4%) and high-speed running (-2.5%), with a contemporaneous increase in walking distance (1.4%), was noted in relation to pre-lockdown performance. A reduction in high-speed running was observed in central defenders (p < 0.05), central midfielders (p < 0.01) and forwards (p < 0.05). No significant decrease in sprinting or maximal running velocity was observed. The COVID-19 lockdown negatively influenced the physical performance in professional soccer players.

Comparison of training and match load between metabolic and running speed metrics of professional Spanish soccer players by playing position.

The aims of this study were to compare the training and match load of professional soccer players according to the playing position, and analyse the relationship between the metabolic and running speed metrics. Thirty professional male soccer players belonging to a Spanish First Division team were analysed using global positioning system devices (GPEXE Pro 18.18 Hz) during training and competition (n = 36 training weeks and n = 41 matches). The results showed significant differences between positions on match day; central midfielders covered higher total distance and low- and medium-speed running distance (moderate to large effect size) than central defenders, external defenders and forwards; forwards performed more metabolic power events than central defenders, central midfielders and wide midfielders; and central defenders showed the lowest very-high-speed running. Different patterns were observed in training. Furthermore, the equivalent-distance index showed a strong correlation with accelerations and decelerations events. The main findings were that the physical responses found in training did not correspond with match demands by position; both metabolic and traditional approaches should be used together for load monitoring in professional soccer players; and finally, metabolic power events and the equivalent-distance index seem to be variables that help to differentiate more clearly the characteristics of the player, taking into account their playing position.

Perspectives on Postmatch Fatigue From 300 Elite European Soccer Players.

To examine the general perspectives of elite soccer players on the time course of perceived postmatch fatigue and the influence of away matches on subjective perceptions. Adopting a cross-sectional study design, we invited 371 subjects from 14 top-division European clubs competing in the Belgian First Division A, English Premier League, French Ligue 1, Italian Serie A, Portuguese Primeira Liga, Russian Premier League, and Swiss Premier League to take part in a short survey on general issues relating to postmatch fatigue measurement and tracking in professional soccer. Three hundred male professional soccer players completed the short questionnaire. For perceptions relevant to the time course of postmatch fatigue, two-thirds of respondents (67%) indicated higher postmatch fatigue perceived 2days (48h) after an official competition. Among these respondents, a higher proportion of answers was observed in wide midfielders (74%), attackers (74%), and central midfielders (68%). Approximately two-thirds of respondents (63%) indicated more than usual and much more than usual perceived postmatch fatigue following away matches. For the first time, our investigation addressed practical aspects that remained unexplored and fundamental to the definition of an optimal player management process following a competition. From a practical standpoint, perspectives of individual elite soccer players substantiated the notion of implementing processes with dedicated recovery protocols within 48hours postmatch and highlighted the need for differential strategies addressing the additional burden of away matches and travel.

Position-specific physical and technical demands during the 2019 COPA América Football tournament.

Despite a substantial body of literature on the physical and technical performance characteristics of football players in Asian and European tournaments, research on South American football players is scarce. The purpose of the study was to examine the physical and technical characteristics of football players according to specific playing positions at the 2019 COPA América tournament. A total of 180 match observations from 13 games were monitored using the InStat tracking system. Players were grouped into the following five playing positions: central defenders (n = 45), wide defenders (n = 46), central midfielders (n = 50), wide midfielders (n = 17), and forwards (n = 22). Descriptive statistics (means ± standard deviations) and the one-way analysis of variance were used to analyse the data. Findings showed that the total distance covered by central midfielders (10 553 ± 763 m) was significantly (p < 0.05) higher than that of central defenders (9226 ± 720 m; effect size (d) = 1.79), wide defenders (9929 ± 633 m; d = 0.89) and forwards (9383 ± 820 m; d = 1.45). Wide midfielders (214 ± 170 m), wide defenders (152 ± 199 m) and forwards (138 ± 94 m) covered greater distances sprinting than central defenders (67 ± 42 m; d = 1.19) and central midfielders (91 ± 66 m; d = 0.95). Concerning technical variables, central midfielders played significantly more passes compared to players in other playing positions (p < 0.05). In relation to crossing, wide defenders completed significantly more crosses than players in other positions (p < 0.05). These findings have direct implications for tailoring tactics so players can meet the physical and technical demands of the game.

Relationship Between Yo-Yo Intermittent Endurance Test-Level 1 and Match Running Performance in Soccer: Still on the Right Path?

Abstract Introduction. The Yo-Yo Intermittent Endurance Test-Level 1 (Yo-Yo IR1) is considered a valuable measurement tool in assessing specific soccer endurance. However, there is a lack of recent research validating this test with regard to match running performance (MRP) in elite-level soccer. Material and Methods. The aim of this study was to evaluate the validity of Yo-Yo IR1 in predicting MRP during elite-level soccer matches. The participants were soccer players who competed in the highest-level Croatian soccer league (23.57 ± 2.84 years, 181.9 ± 5.17 cm, 78.36 ± 4.18 kg), and they were all tested using Yo-Yo IR1 in the middle of the season 2019/2020. The players’ MRP (n = 71) was measured using the Global Positioning System over one-half season, and included the total distance covered, the distance covered in different speed zones, accelerations and decelerations. The association between MRP and Yo-Yo IR1 was identified with Pearson’s correlation. Results. The results indicated that central midfielders and fullbacks achieved significantly higher results in Yo-Yo IR1 than forwards and central defenders (F-test: 29.80; p &lt; 0.01; large effect size). Higher results in Yo-Yo IR1 were correlated with the match amount of (i) the total distance covered (r = 0.65); (ii) high-speed running (r = 0.42); (iii) high-intensity distance covered (r = 0.36); (iv) total accelerations (r = 0.37); and total decelerations (r = 0.42). Conclusions. The established associations between Yo-Yo IR1 and MRP in this study confirmed the validity of Yo-Yo IR1 in predicting MRP in professional soccer today.

Position specific physical performance and running intensity fluctuations in elite women's football.

The purpose of the present study was to investigate the physical performance of elite female football players during match play along with transient alterations in running performance following 1- and 5-min univariate peak periods. 54 elite female players from four top-level Norwegian teams were monitored for one season (n=393match observations), and physical performance data collected using STATSport GPS APEX. Results revealed significant differences in physical performance between the positions during full match play, particularly between wide and central players. Both full backs (FBs) and wide midfielders (WMs) covered more total distance (TD), high-speed running distance (HSRD), and sprint distance (SpD) than center backs (CBs) (p<0.05-0.001), while WMs also covered more HSRD than both central midfielders (CMs) (p<0.01) and forwards (FWs) (p<0.05), and more acceleration -and deceleration distance (Accdist and Decdist ) than both CBs and CMs (p<0.01-0.001). A similar pattern was observed for the peak period analysis, with FBs and WMs covering more SpD in peak 1min than CBs and CM (p<0.001) and more SpD in peak 5-min than CBs, CMs, and FWs (p<0.001). Irrespective of the variable analyzed, greater distances were covered during the peak 5-min period than in the next-5 and mean 5-min periods (p<0.001). Significant (p<0.001), but small to trivial (Cohen's Dz : 0.07-0.20), decreases in distance covered were also observed for each variable following each univariate peak 5-min period. In conclusion, practitioners should account for differences in physical performance when developing training programs for female football players and be aware of transient reductions in physical performance following univariate peak 1- and 5-min periods. Specifically, the very high intensity in 1-min peak periods adds support to the principal of executing speed endurance activities during training to mirror and be prepared for the physical demands of match play.

FIFA U-20 월드컵 한국 축구 대표팀 선수의 경기 중 포지션별 이동거리 및 활동형태 분석

The purpose of this study was to analyze moving distance and movement patterns of Korean national football team players by playing positions at the 2019 FIFA U-20 World Cup. Using a video analysis program, we analyzed 54 players who played a full match in 7 games of Korean national football team, and the positions were classified into the central defender(CD), the side defender(SD), the central midfielder(CM), the side midfielder(SM), and forward(FW). For the moving distance, we analyzed the total distance, the distance of the first half, the distance of the second half, and the distance per minute. As a result, we found that CM and SM covered greater total distances than did CD and FW. Also, we found that CM and SM covered larger distances than CD and FW did during the first half and that CM showed the greatest distance than CD and FW did during the second half. Moreover, we found that CM and SM covered greater distances per minute than CD and FW did. In addition, we analyzed the movement patterns by zone 1(walk), zone 2(jog), zone 3(run), zone 4(high intensity run: HIR), zone 5(sprint), and zone 4 & 5 distance per minute. As a result, we found that CD and FW covered larger distances than SD and CM did in zone 1. Also, CM covered the greatest distance in zone 2 than any other positions did, and CM and SM covered larger distances than CD and FW did in zone 3. We also found that SM demonstrated greater distances than CD and FW did in zone 4 and that SM showed larger distances than CM did in zone 5. Finally, SD and SM demonstrated the greatest distances than did any other positions in zone 4 & 5 distance per minute.

Fluctuations of Training Load Variables in Elite Soccer Players U-14 throughout the Competition Season.

Excessive daily training load (TL) can affect the musculoskeletal system health of youth elite soccer players. The purposes of this study were (i) to describe the TL and session rating of perceived exertion (s-RPE) throughout the competition season; (ii) to analyze the weekly (w) differences of acute (daily) workload (wAWL), chronic workload (wCWL), acute–chronic workload ratio, training monotony (wTM), and training strain (wTS) among three periods over the season (early-, mid-, and end-season) by playing position; and (iii) to compare the TL variables during competition periods for the whole team. Twenty young elite soccer players in the under-14 category participated in this study. The game positions were considered as six wide defenders and wide midfielders (WM), five central defenders and central midfielders, and four strikers (ST). Daily monitoring was continued for 26 weeks during a full competition season. According to the league schedule, the season was divided into three periods: early-season from w1 to w8, mid-season from w9 to w17, and end-season from w18 to w26. The main results were that the higher TLs were detected in the early- and mid-season. There was a wAWL and wCWL decrease for all playing positions from early- to mid- and end-season, but the wCWL change was significant only from early- to mid-season (p ≤ 0.05). For all playing positions but ST, there was a considerable wTM increase from early- to mid-season. When compared with all other playing positions in terms of wAWL and wCWL, WM showed significantly greater values (p ≤ 0.05). Throughout the season periods, all workload indicators showed a considerable reduction, although there was a significant increase in the three other workload-derived variables (all with p ≤ 0.05) and namely: (i) wACWLR from mid- to end-season; (ii) wTM from early- to mid- and end-season; and (iii) wTS from early- to mid-season. Daily training load and s-RPE had significant fluctuations during all macrocycles of the competition season (p ≤ 0.05). In addition, in the mid-season, wTM and wTS were higher. Training load monitoring (in terms of, e.g., wAWL, wCWL, and s-RPE) could be the key for coaches of soccer teams to prevent overtraining and injury, especially in U-14 players, who are more susceptible to being affected by high workload.

The Influence of Time Winning and Time Losing on Position-Specific Match Physical Demands in the Top One Spanish Soccer League.

The aim of the present study was to analyze the influence of time winning and time losing on position-specific match physical demands with and without ball possession in the top Spanish professional soccer league. All matches played in the First Spanish soccer league over four consecutive seasons (from 2015/16 to 2018/19) were recorded using an optical tracking system (i.e., ChyronHego), and the data were analyzed via Mediacoach®. Total distance (TD), and TD > 21 km·h−1 covered with and without ball possession were analyzed using a Linear Mixed Model, taking into account the contextual variables time winning and losing. Results showed that TD and TD > 21 km·h−1 covered by central midfielders (0.01 and 0.005 m/min, respectively), wide midfielders (0.02 and 0.01 m/min, respectively), and forwards (0.03 and 0.02 m/min, respectively) significantly increased while winning (p < 0.05). By contrast, TD and TD > 21 km·h−1 covered by central defenders (0.01 and 0.008 m/min, respectively) and wide defenders (0.06 and 0.008 m/min, respectively) significantly increased while losing (p < 0.05). In addition, for each minute that teams were winning, total distance with ball possession (TDWP) decreased, while, for each minute that teams were losing, TDWP increased. Instead, TDWP > 21 km·h−1 obtained opposite results. Total distance without ball possession increased when teams were winning, and decreased when teams were losing. Therefore, the evolution of scoreline significantly influences tactical–technical and physical demands on soccer matches.

In-season monotony, strain and acute/chronic workload of perceived exertion, global positioning system running based variables between player positions of a top elite soccer team

BackgroundThe interpretation of the load variations across a period seems important to control the weekly progression or variation of the load, or to identify within- micro and mesocycle variations. Thus, the aim of this study was to describe the in-season variations of training monotony, training strain, and acute: chronic workload ratio (ACWR) through session rating of perceived exertion (s-RPE), total distance and high-speed running (HSR) according to playing positions in an elite soccer team.MethodsSeventeen professional players from an European First League team participated in this study. They were divided four central defenders (CD), three wide defenders (WD), four central midfielders (CM), three wide midfielders (WM) and three strikers (ST). The players were monitored daily over a 41-week period of competition where 52 matches occurred during the 2015–2016 in-season. Through the collection of s-RPE, total distance and HSR, training monotony, training strain and ACWR were calculated for each measure, respectively. Data were analysed across ten mesocycles (M: 1–10).ResultsThe main results showed significant differences (p < 0.05) for TMs-RPE between CD vs. ST (moderate effect) in M2; between CD vs. CM (moderate effect) for TS of s-RPE; between CD vs. ST moderate effect) in M6 for ACWR of s-RPE. In addition, there was significant difference between CM vs. ST (moderate effect) in M2 for TS of TD; between WD vs. ST (moderate effect) in M3 for ACWR of TD. Moreover, there were significant differences for TM of HSR between CD vs. WD (very large effect); CD vs. WD (moderate effect) in M4 for TS of HSR.ConclusionsThe present study presents new insights to coaches and technical staff about the variation profiling of TM, TS, and ACWR calculated with internal and external load measures, between player positions during 10 mesocycles.

Impact of Possession and Player Position on Physical and Technical-Tactical Performance Indicators in the Chinese Football Super League.

The purpose of this study was to investigate the impact of high (HPBPT) and low percentage ball possession teams (LPBPT) on physical and technical-tactical performance indicators in the Chinese Football Super League (CSL). Eight physical performance indicators and 26 technical-tactical performance indicators from all 240 matches from season 2018 were analyzed, as well as three contextual variables (team strength, quality of opposition, and match location). Players were divided according to five positions: fullbacks, central defenders, wide midfielders, central midfielders, and attackers. A k-means cluster analysis was conducted to classify all match observations into two groups: HPBPT (n = 229) and LPBPT (n = 251). A mixed linear model was fitted with contextual variables as covariates. When significant interactions or main effects were detected, a post hoc comparison was used to compare physical and technical/tactical differences between HPBPT and LPBPT. Results showed that central defenders and fullbacks covered more high-intensity and sprint running distance in the high possession teams, while wide midfielders and forward covered more high-intensity and sprint running distance in the low possession teams. Meanwhile, players from high ball possession teams were strong in technical indicators, especially in attacking organization. These results may help coaches to understand current football development trends and develop suitable training plans and tests for elite football players.

Analysis of Running Performance in the Offensive and Defensive Phases of the Game: Is It Associated with the Team Achievement in the UEFA Champions League?

Although associations between running performance (RP) with ball possession and team achievement in soccer are often hypothesized, actual knowledge of this association in elite soccer remains limited. Therefore, this study aimed to evaluate players’ RPs according to ball possession to determine its possible influence on team achievement in the UEFA Champions League (UCL). The players’ RPs (n = 244) were collected during UCL group stage matches (n = 20) in the 2020/21 season using the semiautomatic video system InStat Fitness. Then, players’ RPs were classified according to the specific playing position: central defenders (CD; n = 79), fullbacks (FB; n = 65), central midfielders (CM; n = 55), wide midfielders (WM; n = 28) and forwards (FW; n = 17). RPs were observed in the attacking phase (AP, i.e., when the team was in possession of the ball) and defensive phase (DP, i.e., when the team did not have possession of the ball) of the game, and included the total distance covered (m) and distance covered in different categories: walking (&lt;7.1 km/h), jogging (7.1–14.3 km/h), running (14.4–19.7 km/h), high-intensity running (&gt;19.8 km/h), high-speed running (19.8–25.1 km/h) and sprinting (&gt;25.2 km/h). Team achievement was defined by the total group points earned (TGP) at the end of the group phase of the UCL and by match outcome (win, draw, loss) of single matches. The results indicated that the total, walking and jogging distances covered were negatively and positively associated with TGP (Pearson’s correlations from 0.30 to 0.73; all p &lt; 0.05) in the AP and DP of the game, respectively. Won matches were characterized by significantly lower and higher values of total, walking and jogging distances covered in AP and DP of the game, respectively (F tests: from 7.15 to 22.5, all p &lt; 0.01; all small to medium effect sizes). In addition, RPs in the AP and DP of the game explained only 37.2% of the variance in the TGP. These findings demonstrate that the influence of RP on team achievement in UCL is limited in both the AP and DP of the game.

Effects of Match Location, Quality of Opposition and Match Outcome on Match Running Performance in a Portuguese Professional Football Team.

The aim of this study was to analyze the effects of match location, quality of opposition and match outcome on match running performance according to playing position in a Portuguese professional football team. Twenty-three male professional football players were monitored from eighteen Portuguese Football League matches during the 2019–2020 season. Global positioning system technology (GPS) was used to collect time-motion data. The match running performance was obtained from five playing positions: central defenders (CD), fullbacks (FB), central midfielders (CM), wide midfielders (WM) and forwards (FW). Match running performance was analyzed within specific position and contextual factors using one-way analysis of variance (ANOVA) for repeated measures, standardized (Cohen) differences and smallest worthwhile change. CM and WM players covered significantly greater total distance (F = 15.45, p = 0.000, η2 = 0.334) and average speed (F = 12.79, p < 0.001, η2 = 0.294). WM and FB players covered higher distances at high-speed running (F = 16.93, p = 0.000, η2 = 0.355) and sprinting (F = 13.49; p < 0.001, η2 = 0.305). WM players covered the highest number of accelerations (F = 4.69, p < 0.001, η2 = 0.132) and decelerations (F = 12.21, p < 0.001, η2 = 0.284). The match running performance was influenced by match location (d = 0.06–2.04; CI: −0.42–2.31; SWC = 0.01–1.10), quality of opposition (d = 0.13–2.14; CI: –0.02–2.60; SWC = 0.01–1.55) and match outcome (d = 0.01–2.49; CI: −0.01–2.31; SWC = 0.01–0.35). Contextual factors influenced the match running performance with differential effects between playing positions. This study provides the first report about the contextual influence on match running performance in a Portuguese professional football team. Future research should also integrate tactical and technical key indicators when analyzing the match-related contextual influence on match running performance.

Effects of Age on Match-related Acceleration and Deceleration Efforts in Elite Soccer Players.

The aim of this study was to examine the effects of chronological age on acceleration and deceleration match performance in professional soccer players. A total of 5317 individual match observations were collected on 420 professional players competing in the Spanish LaLiga during the 2018-2019 season, using a multiple-camera computerised tracking system (TRACAB; ChyronHego, Melville, NY, USA). Players were classified using a k-means cluster analysis into four different age groups: 17-23 years, 24-27 years, 28-30 years, and 31-38 years. Linear mixed models were adjusted to compare the players' match performance according to their age group and playing position (central defenders, external defenders, central midfielders, external midfielders, and forwards). The results showed that players aged between 31-38 years performed a significantly less total number of accelerations (ES=0.30-0.48) and decelerations (ES=0.29-0.49) in comparison with younger players. These age-related physical performance declines were more pronounced among central defenders, central midfielders, and forwards. However, no significant effects were obtained for players' maximum acceleration and deceleration capacities. The current findings provide useful information for coaches and strength and conditioning specialists to better understand the effects of age on players' physical performance and to develop age-tailored training programs.

How football team composition constrains emergent individual and collective tactical behaviours: Effects of player roles in creating different landscapes for shared affordances in small-sided and conditioned games

The aim of the present study was to examine how team composition of players with different roles constrains individual and collective tactical behaviours, and ball possession effectiveness, during competitive 3 vs 3 small-sided and conditioned games (SSCGs) in youth soccer players. Fifteen male players (under 15 yrs, mean age 13.2 ± 1.03 years, mean years of practice: 4.2 ± 1.10 years) from the same club participated in this study. For analysis purposes, on advice from the coaching staff, participants were categorised according to their main team performance role, resulting in sub-samples of 5 defenders (centre-backs = 2 and full- backs = 3), 7 midfielders (central midfielders = 3 and wide midfielders = 4) and 3 attackers (forwards). In order to assess participant tactical behaviours, a notational analysis system was created with four categories: i) team behaviours, ii) individual players’ offensive actions, iii) individual players’ defensive actions, and iv), ball possession effectiveness. Analysis of players’ offensive actions revealed that the team composed only of midfielders revealed a higher frequency of diagonal and vertical passes in relation to the attackers’ team. In offensive individual actions, the attackers’ team revealed more dribbles in relation to the teams of defenders and midfielders. Analysis of ball possession effectiveness revealed that the team of defenders achieved higher values of shots on goal compared to the team of midfielders. These findings exemplified how playing role constrains the emergence of different collective behaviours and individual actions in 3 vs 3 SSCGs.

Scanning activity in elite youth football players

ABSTRACT The purpose of this study was to analyse the scanning behaviour of elite youth football players across different playing positions and age groups during high-level matches. Data was obtained by filming the 2018 UEFA European U17 and U19 Championship semi-finals and finals. A total of 53 outfield players from the four teams that reached the finals were analysed in both their respective semi-final and final matches, resulting in a total of 1686 attacking play situations. Ecological psychology provided us with the theoretical rationale for the study and informed our research hypotheses and interpretations. We found that U19 players performed more scans than U17 players. A positive relationship between scan frequency and pass success was also found. The results further suggest that opponent pressure and pitch position are both critical contextual factors that may influence scanning behaviour. In addition, central midfielders and central defenders were found to have higher scan frequencies than players in other positions. Our results support and extend previous research, suggesting that playing positions and age groups are important factors that impact visual perception and specifically scanning in football. Potential implications for coaches and recommendations for future studies are discussed.

Features of physical and technical-tactical preparedness of young football goalkeepers 13-14 years old

The research results of the physical development level, indicators of technical and tactical actions of young football players aged 13–14 of different game roles are presented. The research involved 46 young players aged 13-14 of FC "Arsenal" in Kharkov, including 6 goalkeepers, 8 central defenders, 8 wing defenders, 8 central midfielders, 8 wing midfielders, 8 forwards. The following methods were used: theoretical analysis and generalization of scientific and methodological literature, pedagogical testing, and mathematical statistics. Quantitative indicators of motor actions of young football players of 13-14 years of different game role according to the results of 10 calendar games are determined. It was established that the quality of performance of technical and tactical actions of young football players was not the same for players of different game roles. Goalkeepers mainly make long and short passes (29.8 ± 1.19 and 27.2 ± 1.16% of the total number of technical and tactical actions). The largest number of movements with the back forward, cross step and additional step was made by the goalkeeper (12.3; 7.0; 2.6% of game actions per game), which were statistically significantly higher in relation to all field players (p &lt;0.001). Goalkeepers during the game perform more jumps (32.4 ± 1.48% of all motor actions) and throwing the ball (26.4 ± 1.48%). Goalkeepers’ indicators of speed and power capabilities (in the test "vertical jumping") were statistically significantly superior (p &lt;0.05) to players of all other lines. The correlations between the test indicators that reflect the level of goalkeepers’ physical fitness were determined. A statistically significant correlation was established between the indicator "vertical jumping" and running 30 m (ρ = -0.82, p &lt;0.05), indicators of starting and distance speed (ρ = 0.84 and ρ = 0.86, p &lt;0.05), the indicator "running 10 m on the move" with a 6-minute run, which characterized the overall endurance (ρ = -0.83, p &lt;0.05). Goalkeepers are characterized by the relationship between all technical and tactical actions of the game and the level of motor skills development, namely the statistical significance of the correlation of speed and speed-power qualities with technical and tactical indicators.

Fluctuations in Well-Being Based on Position in Elite Young Soccer Players during a Full Season.

The current study surveyed weekly and daily variations of well-being ratings relative to the Hooper Index (HI): fatigue (wFatigue), stress (wStress), delayed onset muscle soreness (wDOMS), and sleep quality (wSleep) during a soccer season based on players’ positions. The full-season was divided into three meso-cycles: Early season, week (W)1 to W7; Mid-season, W8 to W13, and End-season, W14 to W20. Twenty-six young players participated in the study (age, 15.5 ± 0.2 years; height, 172.9 ± 4.2 cm; body mass, 61.4 ± 5.6 kg; body fat, 8.6 ± 2.9%; VO2max, 48.4 ± 2.4 mL.kg−1·min−1; maturity offset, 1.9 ± 0.3 years). Participants played in the same team and competed in Iran national under-16 competitions. Well-being status was monitored on training days using the HI questionnaire. The main result was a significant difference between well-being status 5 days before match day (MD) and 4 days before MD, compared to MD for all playing positions (p ≤ 0.001). The highest and lowest records occurred during End-season for wDOMS (strikers = 11.5 ± 8.4 arbitrary units (AU)), Early season (central defenders = 9.5 ± 0.7 AU) and for wFatigue (central midfielders = 11.4 ± 0.9 AU), and Early season (wide defenders = 9.7 ± 0.7 AU), respectively. Overall, the results showed a significant increase in wStress and wSleep for all players’ positions from Early- to End-season. The main application of this study is to make coaches aware of their players’ well-being fluctuations throughout the full season, especially in young elite soccer players, and to avoid injuries, overtraining, and overreaching as much as possible.

The Effect of Contextual Variables on Match Performance across Different Playing Positions in Professional Portuguese Soccer Players.

This study investigated the position-specific physical demands of professional Portuguese players. The effects of situational variables on the physical performance demands were also analysed (match location, match half and match result). Match performance observations were collected using Global Navigation Satellite System devices across 11 matches during a competitive season (2019–2020). Data were analysed according to five playing positions: goalkeepers (n = 11), central defenders (n = 42), wide defenders (n = 31), central midfielders (n = 34), open attackers (n = 28), and centre forwards (n = 14). Central midfield players completed the greatest total distance (10,787 ± 1536 m), while central defenders covered the least distance (9272 ± 455; p < 0.001). Open attackers covered the greatest high and very-high-speed distance (1504 ± 363 m), number of high-speed decelerations per match (11 ± 4) and were the fastest players (30.6 ± 1.5 km/h), along with center forwards (30.6 ± 2.0 km/h), versus all other positions (p < 0.05). Greater distances were performed in teams that were winning (9978 ± 1963 m) or drawing (10,395 ± 875 m) versus losing (9415 ± 2050) p = 0.036 and p = 0.006, respectively. Increases in distance covered at walking speeds were observed during the 2nd half (1574 ± 179 m) compared with the 1st half (1483 ± 176; (p < 0.003). A higher number of decelerations across all speeds were performed in the 1st half (144 ± 39) versus the 2nd half (135 ± 37). The distance covered in home matches (10,206 ± 1926 m) far exceeded away matches (9471 ± 1932 m; p < 0.001). The number of faster accelerations were higher in away (7 ± 5) versus home matches (6 ± 4; p < 0.049). The data demonstrate the different physical demands of each playing position and suggest that situational variables influence physical performance. These findings suggest position-specific physical training is required to condition players for the bespoke demands of each playing position.