Physical match demands across different playing positions during transitional play and high-pressure activities in elite soccer.

This study explored physical match demands across different playing positions during transitional play, to inform the need for position-specific training interventions. Data was collected using 10 Hz GPS units from 10 competitive matches including 23 elite soccer players of the 1st Polish Division (Ekstraklasa) in season 2020-21. A total of 4249 positional observations were made; center backs (n = 884), full backs (n = 972), central defensive midfielders (n = 236), central attacking midfielders (n = 270), central midfielders (n = 578), wingers (n = 778), and attackers (n = 531). Match data reflected distances covered per minute (m · min-1): total distance (TD), high-speed running distance (HSRD, > 19.8 km · h-1), sprint distance (SD, > 25.2 km · h-1), and the frequency of high-intensity accelerations and decelerations (A+D, > 3 m · s-2; n · min-1). Total absolute sprint distance (SD, > 25.2 km · h-1) and total relative sprint distance (Rel B5) were also quantified. A univariate analysis of variance revealed position-specific differences. Significant effects of position were found for all analysed metrics during transitional play (large ESs; p <.001). Central attacking midfielders displayed higher TD (m · min-1), fullbacks covered highest SD (m · min-1) and wingers achieved the highest A+D (n · min-1) (p ≤ 0.05). Centre backs displayed the lowest physical outputs when compared to all other positions, except in A+D (n · min-1) during defensive transitions (p ≤ 0.05). Attackers displayed the highest physical metrics during high pressure activities (p ≤ 0.05). Coaches should carefully consider positional transitional demands to better inform training design. With specific attention paid to drills that replicate game play.

The impact of a mid-season FIFA World Cup™ on injury occurrence and patterns in French professional soccer clubs.

This study retrospectively compared the effect of holding the 2022 FIFA World Cup™ (WC) mid-season (season 2022/23) on injury rates and patterns in French Ligue 1 soccer clubs. Epidemiological data in 17 clubs were prospectively recorded by their physicians. Time-loss injuries (injuries leading to a player being unable to fully participate in play over the following 72-hour period) were compared with those reported during a regular season (2021-22). In the WC season, an increase of approximately 23% (training + match-play) was observed for both the total number of injuries and knee, ankle and muscle injuries combined. Incidences for match-play injury overall and for the knee, ankle and muscle regions combined and the hamstrings and calf regions specifically also rose significantly (range: p < 0.05-p < 0.01). These results suggest that injury occurrence and patterns in French L1 soccer clubs were substantially affected during the 2022/23 season when a mid-season WC was held.

To train or not to train (on match day)? Influence of a priming session on match performance in competitive elite-level soccer.

This study examined the effect of a morning priming session consisted of stretching, mobility, core and lower-body resistance, and reactive agility exercises on match performance in elite-level soccer players. Information on physical and technical performance was collected during competitive matches (n = 32) and subsequently classified as those preceded or not preceded by a priming session. Results showed significantly increased (i) distance covered overall (Cohen's d (d) = 0.34, p = 0.011), in moderate-intensity (d = 0.52, p = 0.001) and high-intensity running (d = 0.30, p = 0.024), and (ii) frequency of duels (d = 0.26, p = 0.050) in matches preceded by a priming session compared to those not preceded by a priming session. These findings show that players' physical performance was notably enhanced due to the pre-match routines that the team implemented on match day, while technical performance was in general similar irrespective of whether a priming session was implemented or not before the match. Therefore, morning priming session implemented on match day can be recommended as an effective pre-match strategy to increase players' physical performance in soccer without negative consequences on technical performance.

Anthropometric and physical characteristics in U16, U18 and U20 elite French youth rugby union players.

The aims of this study in elite youth French players were to 1) describe the anthropometric and physical characteristics of international and non-international players from U16 to U20, and 2) compare these characteristics across age categories and playing standard (international or non-international). Altogether, 1423 players from the French Rugby Federation's academies participated in a physical testing battery, part of its national young player development pathway. From seasons 2010 to 2020, players were assessed for anthropometric (body mass and height), off-field (bench press; isometric squat, vertical jump) and on-field physical characteristics (aerobic capacity: maximal aerobic speed [MAS]; speed: 10-m, 50-m sprint). A 2-way mixed model analysis of variance (ANOVA) was used to compare physical characteristics across age categories and playing standards. Two separate models were used for forwards and backs. A main statistical effect was observed for age category and playing standard (range p < 0.05 -p < 0.001). Pair-wise category comparisons showed that older players were generally taller, heavier, stronger, faster and demonstrated better aerobic qualities than younger peers. The same results were observed for INT compared with NI players while INT forwards were also taller and heavier than NI peers (range p < 0.01 -p < 0.001). Findings revealed a clear progression in anthropometric characteristics and physical qualities throughout the age development pathway in elite young French rugby players. Findings also identified certain physical qualities (strength, power and speed) necessary at younger levels to achieve international standard.

Worst Case Scenarios in Soccer Training and Competition: Analysis of Playing Position, Congested Periods, and Substitutes.

Aim: To understand mean (WCSmean) and peak (WCSpeak) worst case scenarios within training and game play in male professional soccer. Methods: Thirty-one (n = 31) first team players were monitored across 37 matches and 14 MD-3 sessions. Playing status was distinguished, football drills analyzed, and performance explored in long-period: >6 days, moderate-period: 5-6 days, and congested-period: ≤4 days. Relative total distance (TD), high-speed running distance (HSRD, >19.8 km·h-1), sprint distance (SD, >25.2 km·h-1), accelerations/decelerations (A+D, >3 m·s-2), accelerations (Acc, >3 m·s-2), and decelerations (Dec, >-3 m·s-2) were measured as well as Maximum acceleration (Max Acc; m·s-2) and deceleration (Max Dec; m·s-2). Results: Analysis of variance found differences between matches and training in WCSmean for TD, HSRD, SD, and Max Dec in all positions (p < .001; partial η2 > .275). Fullbacks displayed differences between match and training in Max Acc (moderate ESs; p < .001), while center backs and central midfielders in Max Dec (large ESs; p > .05). Main effects of playing status were discovered for all metrics except Max Dec (p < .001; partial η2 > .124). Analysis showed differences between long- and congested-period for A+D and Dec (large ESs; p ≤ .05). Conclusions: Findings provide more insights into short peak intensity demands of soccer showing that the maximum high velocity action of acceleration and deceleration is not being replicated in training. Nonstarters lack maximum intensity exposure in matches (WCSpeak) increasing the gap between training and competition even higher during congested fixture periods.

Peak Running Demands in Elite Women's Rugby Sevens and Rugby Union Match Play: A Comparative Study.

PURPOSE: In women's rugby, players regularly interchange between the rugby sevens (R7) and rugby union (RU) formats. Yet, the game demands and particularly the physical aspects respective to both formats vary and players must be able to respond accordingly. The aim of this study was to compare peak running demands in R7 and RU players. METHODS: A total of 51 international women players participated. HSBC World Sevens Series (n = 19) and Six Nations Rugby Union tournament matches (n = 10) were analyzed for a total of 437 individual match observations. Global positioning systems were utilized to measure total (in meters) and high-speed (above 16 km·h-1, in meters) distance and frequency of accelerations (above 2.5 m·s-2, n) during different rolling-average periods (1-7 min) to obtain peak running activity values. Power law modeling was used to obtain slope and intercept. For all variables, peak values and the value at the 90th percentile (P90) were analyzed. RESULTS: No intercept difference (P = .25; -0.12 ± 0.17) was observed between formats for total distance (161 vs 155 m·min-1). In contrast, R7 players reported a higher intercept (P = .01; -0.29 ± 0.17) for high-speed distance (66 vs 51 m·min-1), while the intercept was higher (P = .01; 0.31 ± 0.20) in RU for accelerations performed (6.1 vs 5.4 n·min-1). Regarding P90, higher values (P < .001) were observed in R7 for total and high-speed distance and accelerations. CONCLUSIONS: While peak overall intensity was similar, P90 on the high-speed spectrum was higher in R7. Information on the most demanding match-play periods specific to both women's rugby formats can inform training specificity by tailoring sessions to ensure sufficient exposure to these peak demands and, consequently, aid transitioning between formats.

Typical weekly physical periodization in French academy soccer teams: a survey.

In elite-level youth soccer players, weekly training periodization is of paramount importance to plan for short- and long-term physical development. The present study investigated current practices for physical periodization strategies in elite male French academies. An online survey was completed by elite French academies strength and conditioning coaches to determine the typical weekly periodization with particular reference to daily training in relation to match day (MD) in youth soccer players. The survey attempted to characterize the importance of physical development compared to match result, and practices used (expected difficulty and content) for each training session according to duration, exercises, and objective. The frequency rates of the responses were compared using two-tailed Chi-square tests with the significance level set at p < 0.05. Fortyfive questionnaires were analyzed. Respondents indicated that their training sessions focused mainly on physical development (95.6%) rather than match result. Active recovery (34.2%) and aerobic conditioning exercises (40.8%) were primarily conducted on MD+1 and MD+2 using passing circuits and aerobic technical drills. Physical development was mostly pursued during sessions on MD-4 (38.8%) and MD-3 (37.3%). The number of large-sided games was highest on MD-3 (58.1%). On MD-2 and MD-1, a decrease in the training load was highlighted, with speed (40.4%) and tapering sessions (52.4%) mostly implemented. Intensive use of small-sided games (92.3%) and reactivity exercises was observed at MD-1 (100.0%). Our results revealed discrepancies between the physical objectives set for each day and the content implemented, which could potentially be more physically demanding than expected.

Recovery of kicking kinematics and performance following repeated high-intensity running bouts in the heat: Can a rapid local cooling intervention help young soccer players?

The effects of a cooling strategy following repeated high-intensity running (RHIR) on soccer kicking performance in a hot environment (>30ºC) were investigated in youth soccer players. Fifteen academy under-17 players participated. In Experiment 1, players completed an all-out RHIR protocol (10×30 m, with 30s intervals). In Experiment 2 (cross-over design), participants performed this running protocol under two conditions: (1) following RHIR 5 minutes of cooling where ice packs were applied to the quadriceps/hamstrings, (2) a control condition involving passive resting. Perceptual measures [ratings of perceived exertion (RPE), pain and recovery], thigh temperature and kick-derived video three-dimensional kinematics (lower limb) and performance (ball speed and two-dimensional placement indices) were collected at baseline, post-exercise and intervention. In Experiment 1, RHIR led to small-to-large impairments (p < 0.03;d = -0.42--1.83) across perceptual, kinematic and performance measures. In experiment 2, RPE (p < 0.01; Kendall's W = 0.30) and mean radial error (p = 0.057; η2 = 0.234) increased only post-control. Significant small declines in ball speed were also observed post-control (p < 0.05; d = 0.35). Post-intervention foot centre-of-mass velocity was moderately faster in the cooling compared to control condition (p = 0.04; d = 0.60). In youth soccer players, a short cooling period was beneficial in counteracting declines in kicking performance, in particular ball placement, following intense running activity in the heat.

[Hamstring muscle injury in football players. Part 2 : preventive strategies]. / La lésion musculaire des ischio-jambiers chez le footballeur. Partie 2 : stratégies de prévention lésionnelle.

Prevention of hamstring injuries represents an important issue for football players and clubs. Preventive strategies can be effective if they include multiple dimensions and are well-structured. Five points appear essential in order to obtain a high-quality preventive strategy: progressive muscle strengthening, optimal workload management, lumbopelvic stability exercises, development of physical condition and optimization of sprint technique. While recognizing the limitations of preventive screening and the difficulty of predicting future injury, screening tests appear relevant for the identification of an individual risk profile for each footballer and in defining each player's work priorities. Finally, secondary prevention starts with the implementation of rigorous and high-level rehabilitation, as well as a special attention to players with a history of hamstring injury.

La prévention des lésions musculaires des ischio-jambiers représente une thématique de première importance pour les joueurs et clubs de football. Les stratégies préventives peuvent se révéler efficaces, à condition d'inclure de multiples dimensions à celles-ci et de structurer ces démarches. Cinq points apparaissent incontournables dans l'optique d'obtenir une stratégie préventive de qualité : le renforcement musculaire progressif et raisonné, la gestion équilibrée de la charge de travail, le travail de la stabilité lombo-pelvienne, le développement de la condition physique et l'optimalisation de la gestuelle de course. Tout en reconnaissant les limites du screening préventif et la difficulté de prédire une future blessure, un état des lieux précis peut s'avérer pertinent pour identifier le profil de risque individuel de chaque footballeur et pour définir les priorités de travail de chacun. Enfin, la prévention secondaire démarre par la mise en place d'une rééducation rigoureuse et structurée, ainsi que par une attention particulière aux joueurs avec antécédents de lésions aux ischio-jambiers.

[Hamstring muscle injury in football players - Part I : epidemiology, risk factors, injury mechanisms and treatment]. / La lésion musculaire des ischio-jambiers chez le footballeur. Partie 1 : épidémiologie, facteurs de risque, mécanismes lésionnels et traitement.

Due to its high frequency and recurrence rate, hamstring injury represents an important issue in football currently. The mechanisms of injury and the main modifiable and non-modifiable risk factors are now well documented and should allow the implementation of effective preventive strategies. In the treatment of the injured player, the physician will have to rely on a close collaboration with a quality sports physiotherapist and implement a series of key elements allowing an optimal return to the soccer field, which means at the same level of performance compared to the pre-injury period and with a minimal risk of recurrence. This article discusses these different elements in the form of a narrative review of the literature.

La lésion musculaire des ischio-jambiers, de par sa fréquence et son taux de récidive élevés, représente une problématique actuelle importante dans le football. Les mécanismes lésionnels et les principaux facteurs de risque modifiables et non modifiables sont désormais bien documentés et devraient permettre la mise en place de stratégies préventives efficaces. Dans le suivi du joueur blessé, le médecin devra compter sur une collaboration étroite avec un kinésithérapeute du sport de qualité et mettre en place toute une série d'éléments clés permettant un retour optimal sur les terrains de football, c'est-à-dire au même niveau de performance comparativement à la période d'avant blessure et avec un risque minimal de récidive. Cet article aborde ces différents éléments sous l'aspect d'une revue narrative de la littérature.

A comparison of running and contact loads in U18 and U20 international rugby union competition.

The purpose of the present study was to characterize and compare locomotor and contact loads in U18 and U20 international rugby union competition during matches, and specifically during peak match-play phases using short rolling epochs and continuous ball-in-play (BIP) sequences. 20 international matches from French national teams were analysed in the U18 and U20 Six Nations Tournament respectively and World Rugby U20 Championship. Running loads were quantified using global positioning devices (16 Hz) and contact loads via video match analysis software. Players were split into forward (U18, n = 29; U20, n = 32) and back positional groups (U18, n = 20; U20, n = 24). Compared with U20 peers, U18 players covered a higher total distance (effect size (ES) = -0.76 ± 0.25) and at high-speeds per minute (> 4 m · s-1; ES = -0.55 ± 0.25) and performed more accelerations (ES = -0.71 ± 0.25). While a greater frequency of BIP sequences > 90 s duration was observed in U20s versus U18s match-play, U18s covered more total distance and high-speed distance (ES = -0.42 ± 0.13 and -0.33 ± 0.13 respectively) per minute during these longer sequences. During peak rolling phases shorter than 4 minutes, no clear differences existed between age categories in running activity, while U20 forwards performed more contact actions than U18 peers. The match-play loads observed in the present international U18 players suggest that they are ready to respond to the overall and peak demands observed in U20 competition. Moreover, the present information on peak activity phases can aid design of overload high-intensity conditioning sessions to respond to the running- and contact-demands identified in those competitions.

Measuring maximal horizontal deceleration ability using radar technology: reliability and sensitivity of kinematic and kinetic variables.

Radar technology has the potential for providing new insights into maximal horizontal deceleration ability. This study aimed to investigate the intra- and inter-day reliability and sensitivity of kinematic and kinetic variables obtained from a novel, maximal horizontal deceleration test, using radar technology. Thirty-eight university sport athletes completed testing for intra-day analysis. Twelve of these participants also completed the deceleration test on a second day for inter-day analysis. The maximal horizontal deceleration test required participants to decelerate maximally following 20 m maximal horizontal sprint acceleration. Reliability was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV%). Sensitivity was evaluated by comparing typical error (TE) to the smallest worthwhile change (SWC). A number of kinematic and kinetic variables had good (ICC > 0.75, CV < 10%) overall intra-day reliability, and were sensitive to detect small-to-moderate changes in deceleration performance after a single familiarisation session. Only kinetic variables had good overall inter-day reliability and were sensitive to detect moderate changes in deceleration performance. The utilisation of this test protocol to assess maximal horizontal deceleration can provide new insights into individual maximal horizontal deceleration capabilities. Future work using this or similar approaches may provide insights into the neuromuscular performance qualities needed to decelerate maximally.

Injury rates and patterns in French male professional soccer clubs: a comparison between a regular season and a season in the Covid-19 pandemic.

This study investigated time-loss injury occurrence and patterns between the first season (2020/21, S2) completed during the Covid-19 pandemic (longer pre-season following cancellation of the 2019/20 season but shorter duration) and a regular season (2018/19, S1) in French Ligue 1 and 2 professional soccer clubs. Epidemiological data were prospectively recorded in a national injury database by each club's physician. In all clubs combined, the mean number of injuries per club was 31.5 and 36.6 in S2 and S1, respectively (-13.9%). Overall match injury incidence (per 1000 hours) in all clubs combined was lower in S2 versus S1 (22.23 vs 25.96, p < 0.01). In Ligue 1 clubs alone, match-play incidences for injury overall (24.92 vs 29.42), muscle strains (10.59 vs 13.24) and strains specifically in the hamstring region (4.52 vs 6.22) were lower in S2 versus S1 (all p < 0.05). No differences in the incidence of match injuries affecting the ankle and knee regions were observed. Changes in the 2020/21 season structure and duration owing to the Covid-19 pandemic seem not to have had a negative effect on injury occurrence and patterns in French professional soccer clubs.

A survey of organizational structure and operational practices of elite youth football academies and national federations from around the world: A performance and medical perspective.

Aim: Medical and performance units are integral components of player development programmes in elite football academies. Nevertheless, the nature of the operational processes implemented by practitioners within clubs and national federations remains unexplored. The aim of the present study, therefore, was to survey elite youth professional football academies from around the world regarding the operational processes adopted by their medical and performance units. Methods: Of the 50 organizations invited, 10 national federations and 25 clubs took part in the survey resulting in a response rate of 70% (95% confidence interval, 56%-81%). The respondents represented three groups: senior club and academy management, performance, and medical staff. Results: The majority (60%-90%) of clubs and national federations reported strategic alignment between senior and academy medical and performance units as well as between academy medical and performance units. Survey responses indicated substantial heterogeneity in the composition and number of medical and performance professionals employed in academies. The majority of respondents agreed their medical and performance departments were effective in utilizing staff knowledge and external sources of knowledge to inform their practice (56%-80%). Performance staff (40%-50%) and physiotherapists (30%-32%) were deemed most influential in injury prevention programmes. During the return-to-play process, the influence of specific practitioners in the medical and performance units was dependent upon the phase of return-to-play. Shared decision-making was common practice amongst performance and medical staff in injury prevention and return-to-play processes. Medical and performance data were generally centralized across the first team and academy in majority (50%-72%) of clubs and national federations. Data were integrated within the same data management system to a higher degree in clubs (68%) vs. national federations (40%). Research and development activity were reported for most academies (50%-72%), and generally led by the head of performance (37%) or team doctor (21%). Research activities were largely undertaken via internal staff (~100%), academic collaborations (50%-88%) and/or external consultants and industry partnerships (77%-83%) in the national federation and clubs. Conclusion: Collectively, these findings provide a detailed overview regarding key operational processes delivered by medical and performance practitioners working in elite football academies.

Modelling the relationships between EEG signals, movement kinematics and outcome in soccer kicking.

The contribution of cortical activity (e.g. EEG recordings) in various brain regions to motor control during goal-directed manipulative tasks using lower limbs remains unexplored. Therefore, the aim of the current study was to determine the magnitude of associations between EEG-derived brain activity and soccer kicking parameters. Twenty-four under-17 players performed an instep kicking task (18 m from the goal) aiming to hit 1 × 1 m targets allocated in the goalpost upper corners in the presence of a goalkeeper. Using a portable 64-channel EEG system, brain oscillations in delta, theta, alpha, beta and gamma frequency bands were determined at the frontal, motor, parietal and occipital regions separately for three phases of the kicks: preparatory, approach and immediately prior to ball contact. Movement kinematic measures included segmental linear and relative velocities, angular joint displacement and velocities. Mean radial error and ball velocity were assumed as outcome indicators. A significant influence of frontal theta power immediately prior to ball contact was observed in the variance of ball velocity (R 2 = 35%, P = 0.01) while the expression of occipital alpha component recorded during the preparatory phase contributed to the mean radial error (R 2 = 20%, P = 0.049). Ankle eversion angle at impact moment likely mediated the association between frontal theta power and subsequent ball velocity (ß = 0.151, P = 0.06). The present analysis showed that the brain signalling at cortical level may be determinant in movement control, ball velocity and accuracy when performing kick attempts from the edge of penalty area. Trial registration number #RBR-8prx2m-Brazilian Registry of Clinical Trials ReBec. Supplementary Information: The online version contains supplementary material available at 10.1007/s11571-022-09786-2.

Biomechanical and Neuromuscular Performance Requirements of Horizontal Deceleration: A Review with Implications for Random Intermittent Multi-Directional Sports.

Rapid horizontal accelerations and decelerations are crucial events enabling the changes of velocity and direction integral to sports involving random intermittent multi-directional movements. However, relative to horizontal acceleration, there have been considerably fewer scientific investigations into the biomechanical and neuromuscular demands of horizontal deceleration and the qualities underpinning horizontal deceleration performance. Accordingly, the aims of this review article are to: (1) conduct an evidence-based review of the biomechanical demands of horizontal deceleration and (2) identify biomechanical and neuromuscular performance determinants of horizontal deceleration, with the aim of outlining relevant performance implications for random intermittent multi-directional sports. We highlight that horizontal decelerations have a unique ground reaction force profile, characterised by high-impact peak forces and loading rates. The highest magnitude of these forces occurs during the early stance phase (< 50 ms) and is shown to be up to 2.7 times greater than those seen during the first steps of a maximal horizontal acceleration. As such, inability for either limb to tolerate these forces may result in a diminished ability to brake, subsequently reducing deceleration capacity, and increasing vulnerability to excessive forces that could heighten injury risk and severity of muscle damage. Two factors are highlighted as especially important for enhancing horizontal deceleration ability: (1) braking force control and (2) braking force attenuation. Whilst various eccentric strength qualities have been reported to be important for achieving these purposes, the potential importance of concentric, isometric and reactive strength, in addition to an enhanced technical ability to apply braking force is also highlighted. Last, the review provides recommended research directions to enhance future understanding of horizontal deceleration ability.

A retrospective analysis of all-cause and cause-specific mortality rates in French male professional footballers.

This study retrospectively compared all-cause and cause-specific mortality in French male professional football players with data from France's national population. Altogether, 6114 individuals born in Metropolitan France or in one of its overseas territories who played at least one competitive match in France's professional football championships between January 1, 1968 and December 31, 2015, were identified and followed up for vital status obtained from a national reference database until December 31, 2015. Data on all-cause and cause-specific mortality were subsequently compared to the expected number of deaths for the national population after standardization for the year, age, and sex. Ratios between observed and expected deaths provided standardized mortality ratios (SMR) along with 95% confidence intervals (95% CI). Linear trends were investigated using the Poisson trend test. Altogether, 662 player deaths were observed. All-cause mortality overall was lower than that of the national population (SMR: 0.69, 95% CI 0.64-0.75). An excess of deaths from dementia was observed in the players (SMR: 3.38, 95% CI: 2.49-4.50) whereas mortality from diseases of the nervous (SMR: 0.64, 95% CI: 0.35-1.08) and cardiovascular systems (SMR: 0.82, 95% CI: 0.70-0.96), and cancer (SMR: 0.67, 95% CI: 0.58-0.76) was lower. Lower overall mortality and that owing to common cardiovascular and cancer-related diseases were reported in French professional football players compared to France's national population. In line with previous studies, however, excess mortality from dementia was observed in the players. Career length was not associated with all-cause or cause-specific mortality. Prospective matched-cohort studies are necessary to identify the neurologic impact of participation in professional football.

Do Changes in Fitness Status, Testosterone Concentration, and Anthropometric Characteristics Across a 16-Month Training Period Influence Technical Performance of Youth Soccer Players During Small-Sided Games?

ABSTRACT: Rodrigues Lopes, RA, Aoki, MS, Carling, C, Vaz Ronque, ER, and Moreira, A. Do changes in fitness status, testosterone concentration, and anthropometric characteristics across a 16-month training period influence technical performance of youth soccer players during small-sided-games? J Strength Cond Res 36(5): 1404-1409, 2022-This study examined the influence of changes in physical capacity, testosterone concentration, and anthropometric characteristics across a 16-month training period on technical performance of youth players during small-sided games (SSG). Thirty-five elite youth players (14.3 ± 0.2 years, 170 ± 6.2 cm, and 61 ± 6 kg) were assessed on 3 occasions (T1, T2, and T3) over the period. A multivariate canonical correlation (MCC) was used to assess the multiple associations between the criterion variable (SSG technical performance) and the predictor variable (physical capacity represented by the Yo-Yo Intermittent Recovery Test Level 1 [Yo-Yo IRT1], testosterone concentration, and anthropometric characteristics). Changes between T1 and T3 were retained for MCC analysis. Multivariate canonical correlation analysis revealed 2 significant functions (R2 = 0.42 and 0.36) indicating a significant relationship between predictor and criterion variables. Changes in Yo-Yo IRT1 performance were the main contributor to the predictor variable, whereas the frequency of tackles/interceptions contributed mostly to the criterion variable (SSG technical performance). These results showed that technical performance in SSG was influenced by changes in Yo-Yo IRT1 performance, suggesting the importance of monitoring in conjunction, intermittent exercise capacity, and technical performance in SSG in youth soccer players. In addition, the stability in technical performance during SSG observed over the experimental period suggests that practitioners could use SSG as a tool for systematic real-world monitoring of technical performance rather than isolated practice drills.

Drop jump neuromuscular performance qualities associated with maximal horizontal deceleration ability in team sport athletes.

The purpose of this study was to investigate associations between, and within, drop jump (DJ) neuromuscular performance (NMP) qualities and maximal horizontal deceleration ability. We also compared DJ NMP qualities in "high" versus "low" horizontal deceleration ability athletes. Twenty-nine university athletes performed: (1) DJs on force plates from 20 (DJ20) and 40 cm (DJ40) heights and (2) maximal horizontal deceleration, measured using radar, following a 20 m acceleration. Maximal horizontal deceleration was evaluated using deceleration (HDEC; m·s-2), across the entire deceleration phase and during early and late deceleration sub-phases. Of the DJ variables assessed, DJ20 and DJ40 reactive strength index (RSI) and concentric mean force had the largest correlations with HDEC (r = -0.54 to -0.61) and the largest differences between high and low HDEC groups (d = 1.20 to 1.40). These correlations were stronger with the early than late HDEC sub-phase (r = -0.54 to -0.66 vs. r = -0.24 to -0.40). Notably, eccentric mean force in DJ40 had large correlations with both DJ20 and DJ40 concentric mean force (r = 0.67 to 0.77), whereas at DJ20 these correlations were small (r = 0.22 to 0.40). Similarly, DJ40 eccentric mean force had a much larger difference between the high and low HDEC groups than DJ20 (d = 1.11 vs. 0.51). These findings suggest DJ RSI from either height may be used as a proxy for HDEC ability, while DJ kinetic analyses should use a higher height to distinguish those with a better capacity to generate eccentric braking forces under increased eccentric loading demands. HIGHLIGHTSPlayers with greater drop jump reactive strength index (RSI) demonstrated superior horizontal deceleration ability.Drop jump RSI had a greater association with the early compared to the late horizontal deceleration sub-phase.Of the drop jump kinetic variables examined, concentric mean force had the largest associations with horizontal deceleration ability.