Dr Stacey Emmonds

The aim of this study was to scope the available peer-reviewed literature on competitive women’s football, identifying and mapping the current research on supporting coaching practice in women’s football. The study reviewed all women’s football related studies scoped by Okholm Kryger et al. (2021) for their relevance to coaching in women’s football. Additionally, an updated search was performed from PubMed (1966–2023), PsycINFO (1967– 2023), Web of Science (1900–2023), Scopus (1788–2023), SPORTDiscus (1892–2023) on 7th December 2023. The author, journal, title, and abstract of all included studies were scoped. Information extracted during the scoping process included: the population, playing level, age group, environment, study type and geographical location of the research. A total of 373 articles were scoped. The publication topic most frequently researched was Performance Analysis – Physical (20%), followed by Performance Analysis - Technical/Tactical (18%) and Maturation/Talent Identification (13%). Most studies were focused on coaching senior players (n=207, 55%) and elite football (n=189, 51%). Despite the volume of research growing each year, it is noticeable there are gaps in the research. Five topics only had a single figure number of articles (Teaching and Learning Strategies, Coach Education/Development, Socio-Cultural Experience’s of Coaching, Coaching Philosophy and Responsibilities/Role in Football). At present given there is a particular emphasis on certain playing levels, playing populations and research topics, there is a dearth of information in certain areas. As such, researchers should work to ensure there is greater thematic depth as well as an increased volume of research in women's football.

Abstract

Beato, M, Datson, N, Clemente, FM, Harper, DJ, Fílter, A, Emmonds, S, Dos' Santos, T, and Jones, PA. Linear and multidirectional speed testing (on-field and off-field) protocols in senior and elite female football. J Strength Cond Res 39(1): e70–e84, 2025—Female football has had a considerable rise in popularity with millions of fans after matches during the recent Women's World Cup. Despite this, the football scientific literature is still biased toward male footballers; therefore, this review aims to present the most recent literature and best practices for assessing linear and multidirectional speed and underpinning physical qualities, and to offer practical recommendations based on the most recent evidence and authors' expertise for practitioners working with female football players. This review categorizes tests as on-field and off-field, highlighting common protocols, their advantages, and the existing limitations. Among the most common on-field tests, we found the change of direction speed, horizontal deceleration, linear sprinting, and curved sprinting; although the suggested off-field tests are multi-joint isometric, single-joint isometric, isokinetic dynamometry, Nordic hamstring, and vertical jumps. These tests are valuable tools for assessing players' physical abilities, serving as a benchmark for tracking physical changes throughout the season, and aiding practitioners in individualizing and optimizing training protocols. This review highlights that strength (eccentric, isometric, concentric, and reactive) and rapid force production are crucial for generating braking and propulsive forces, which underpin linear and multidirectional motion. In conclusion, the evidence and practical suggestions reported in this review will improve the practitioners' knowledge of which tests and the consequent training protocols can be used in senior and elite female football players. But practitioners need to be aware about the scarcity of comprehensive studies on female soccer that hinders a complete understanding of the reliability of all assessment protocols used.

Purpose: Monitoring player readiness to train and perform is an important practical concept in football. Despite an abundance of research in this area in the male game, to date, research is limited in female football. The aims of this study were, first, to summarize the current literature on the monitoring of readiness in female football; second, to summarize the current evidence regarding the monitoring of the menstrual cycle and its potential impact on physical preparation and performance in female footballers; and third, to offer practical recommendations based on the current evidence for practitioners working with female football players. Conclusions: Practitioners should include both objective (eg, heart rate and countermovement jump) and subjective measures (eg, athlete-reported outcome measures) in their monitoring practices. This would allow them to have a better picture of female players’ readiness. Practitioners should assess the reliability of their monitoring (objective and subjective) tools before adopting them with their players. The use of athlete-reported outcome measures could play a key role in contexts where technology is not available (eg, in semiprofessional and amateur clubs); however, practitioners need to be aware that many single-item athlete-reported outcome measures instruments have not been properly validated. Finally, tracking the menstrual cycle can identify menstrual dysfunction (eg, infrequent or irregular menstruation) that can indicate a state of low energy availability or an underlying gynecological issue, both of which warrant further investigation by medical practitioners.

Women’s football has seen rapid recent growth, demonstrated by increased media attention (Fédération Internationale de Football Association [FIFA], 2019), professionalism (many players are now full-time professionals), and recognition by international bodies in the form of new governing strategies (Kryger et al., 2021). This growth looks set to continue with FIFA targeting an increase in female participation worldwide from 13.3 million in 2019 to 60 million by 2026 (FIFA, 2019). Whilst research into the women’s game has also intensified, there remains substantial disparity, and the application of knowledge generated from the men’s game to the women’s game is questionable (Emmonds et al., 2019; Kryger et al., 2021). It is not known and is often questioned whether applying what is known from men’s football to the women’s game can provide an accurate and comprehensive understanding of the women’s side of the game. Given the magnitude of growth in women’s football, along with the continued commitment of investment and increasing participation, there is a need to accelerate high-quality research and disseminate knowledge of practical applications that benefit the health, injury, and performance outcomes of female footballers. Therefore, there are two main aims of this chapter: (1) briefly outline the between-sex differences in match demands, physiology, injury epidemiology, maturation, and health considerations within the context of football and (2) provide practical strength and conditioning recommendations when working with female players.

The FIFA Innovation Programme Challenge 2, focuses on the use of lower-limb mounted devices within Football. The programme was created as a vehicle for new technologies to be allowed to be worn in official FIFA matches, which required six criteria to be met prior to completion. These criteria were, 1) Pass the current FIFA Basic test, 2) Assess new potential methods of testing specific impacts on lower limb devices, 3) Pass the current FIFA Quality test for Electronic Performance Tracking Systems (assessing the validity of the system against a criterion measure), 4) Examine the usability of lower limb mounted devices in actual football match play, 5) Interview club practitioners and gain their feedback on using the systems, and 6) Explore the safety of the system by comparisons to injury surveillance data. In the current case study, a foot-mounted inertial measurement unit (Playermaker), was assessed using the above outlined criteria. The results of the six criteria are presented in the manuscript, with the foot-mounted inertial measurement unit now being permitted to be worn in official match play as an outcome of the FIFA Innovation Programme Challenge 2.

This review highlights the relationship between maturity status, body composition and fitness performance in women's football. The scoping review protocol was registered on the Open Science Framework (osf.io/6wvm5).The literature on growth and maturation in female football players was scoped on PubMed, SCOPUS and Web of Science between February 2023 to April 2025. Studies were considered if they were on, or if they included female football players less than 17 years and included indicators of biological maturation. Two reviewers (FB and BK) selected studies and extracted data. Forty-six studies met the criteria. Regarding maturation the mean age at peak height velocity (APHV) ranged between 12.5 and 12.4 years and the mean age at menarche between 13 and 12.8 years. Body composition varied according to maturation status. Early maturing players are heavier and have greater fat mass than the late maturing ones. Concerning physical performance it was observed that, countermovement jump improved after the PHV, as did change-of-direction ability; for pre-PHV players greatest improvements were observed in sprinting performance and anaerobic endurance. Coaches should consider maturity status while programming their training sessions, not only to adapt their training load more rigorously but also to prevent injuries. However, scientific research on the growth and maturation of female football players is still limited and most of the studies carried out did not consider the players’ training age.

The concurrent validity and between-unit reliability of a foot-mounted inertial measurement unit (F-IMU) was investigated during linear and change of direction running drills. Sixteen individuals performed four repetitions of two drills (maximal acceleration and flying 10 m sprint) and five repetitions of a multi-directional movement protocol. Participants wore two F-IMUs (Playermaker) and 10 retro-reflective markers to allow for comparisons to the criterion system (Qualisys). Validity of the F-IMU derived velocity was assessed via root-mean-square error (RMSE), 95% limits of agreement (LoA) and mean difference with 95% confidence interval (CI). Between-unit reliability was assessed via intraclass correlation (ICC) with 90% CI and 95% LoA. The mean difference for instantaneous velocity for all participants and drills combined was -0.048 ± 0.581 m ∙ s-1, the LoA were from -1.09 to -1.186 m ∙ s-1 and RMSE was 0.583 m ∙ s-1. The ICC ranged from 0.84 to 1, with LoA from -7.412 to 2.924 m ∙ s-1. Differences were dependent on the reference speed, with the greatest absolute difference (-0.66 m ∙ s-1) found at velocities above 7 m ∙ s-1. Between-unit reliability of the F-IMU ranges from good to excellent for all locomotor characteristics. Playermaker has good agreement with 3D motion capture for velocity and good to excellent between-unit reliability.

OBJECTIVE: Quantifying differences in locomotor characteristics of training between two competition levels and between training days within elite female soccer players. METHODS: Foot-mounted inertial measurement unit (Playermaker) data were collected from 293 players from three Women's Super League (WSL; n = 76) and eight Women's Championship (WC; n = 217) teams over a 28-week period. Data were analysed using partial least squares correlation analysis to identify relative variable importance and linear mixed effects models to identify magnitude of effects. RESULTS: WSL players performed more high-speed running distance (HSR; >5.29 m∙s-1), sprint distance (SpD; >6.26 m∙s-1), acceleration (ACC; >3 m∙s-2) and deceleration (DEC; <-3 m∙s-2) distance than WC players. The largest difference between WSL and WC in HSR and HSR per minute occurred on MD-4, (354.7 vs. 190.29 m and 2.8 vs. 1.7 m∙min-1). On MD-2, WSL players also covered greater SpD (44.66 vs. 12.42 m), SpD per minute (0.38 vs. 0.11 m∙min-1) and HSR per minute (1.67 vs. 0.93 m∙min-1). Between training days both WSL and WC teams reduced HSR and SpD but not ACC and DEC distance from MD-4 to MD-2, with MD-4 the highest training day of the week. CONCLUSION: MD-4 is a key training day discriminating between competitive level. HSR and SpD volume and intensity is tapered in WSL and WC players, however there is less clear taper of ACC or DEC. As such, WC teams could increase the volume and intensity of HSR on MD-4 to mimic locomotor activities of those at a higher standard.

Objective Quantify between-match, -player and -team variability and compare whole- and peak-match locomotor characteristics between positions in elite female academy soccer. Method Foot-mounted inertial measurement unit data were collected from 11 Women’s Super League Academy teams (n = 257 players; 171 matches). Differences between positions and variability were analysed using partial least squares correlation analysis (PLSCA) and linear mixed effects. Two latent variables were computed as composite scores of either whole match or peak intensity variables from the PLSCA. Results Between-match variability of whole- and peak-match locomotor characteristics were similar (2 to 24% vs 0.2 to 22%). Between-team and -player variability was higher for whole- than peak-match locomotor characteristics (1 to 20% vs 0.1 to 3%, 8 to 112% vs 0.3 to 77%). From 30 pairwise comparisons, there were two large effect size (ES) differences (p < 0.001), WM had greater whole and peak match composite intensity than CDM. There were 10 moderate ES differences (p < 0.05), with WM greater than CD and CAM, F greater than CD and CDM and WD greater than CDM. All other comparisons were non-significant, trivial or small. Conclusion Whole- and peak- match locomotor characteristics are similar across all outfield positions in elite female academy soccer. Between-match variability was greater for sprint distance than all other locomotor characteristics. Low variability between teams for peak locomotor characteristics means practitioners can be confident using peak reference values from this study and use them to evaluate training drill intensities of tactical-technical drills.

Understanding the maximal intensity periods (MIP) of soccer matches can optimise training prescription. The aim was to establish differences between positions and other contextual factors (match location, match outcome, playing formation and score line) for both external and internal MIP variables and to investigate the differences in the match start time between MIP variables. Maximal moving averages (1 to 10 min) for average speed, high-speed running (5.5-7 m·s-1), sprinting (>7 m·s-1; all m·min-1), average acceleration/deceleration (m·s-2) and heart rate (bpm, % maximal) were calculated from 24 professional youth players across 31 matches. Linear mixed models determined differences in MIP variables between positions, contextual factors and in the match start time of MIPs. Trivial to large positional differences existed in maximal external intensities while central defenders presented the lowest heart rate. It was unclear whether maximal intensities were influenced by contextual factors. MIPs for average speed, acceleration/deceleration and heart rate tend to occur concurrently (ES = trivial) within the first 30 min, while high-speed running and sprinting are likely to occur concurrently (ES = trivial) throughout a whole match. Practitioners could target maximising average speed and average acceleration/deceleration in technical-tactical based training to maximise heart rate responses.

Purpose: To understand the validity of differential ratings of perceived exertion (dRPE) as a measure of girls’ training and match internal loads. Methods: Using the centiMax scale (CR100), session dRPE for breathlessness (sRPE-B) and leg muscle exertion (sRPE-L) were collected across a season of training (soccer, resistance, and fitness) and matches from 33 players (15 [1] y). Differences and associations between dRPE were examined using mixed and general linear models. The authors’ minimal practical important difference was 8 arbitrary units (AU). Results: Mean (AU [SD] ∼16) sRPE-B and sRPE-L were 66 and 61 for matches, 51 and 49 for soccer, 86 and 67 for fitness, and 45 and 58 for resistance, respectively. Session RPE-B was rated most likely harder than sRPE-L for fitness (19 AU; 90% confidence limits: ±7) and most likely easier for resistance (−13; ±2). Match (5; ±4) and soccer (−3; ±2) differences were likely to most likely trivial. The within-player relationships between sRPE-B and sRPE-L were very likely moderate for matches (r = .44; 90% confidence limits: ±.12) and resistance training (.38; ±.06), likely large for fitness training (.51; ±.22), and most likely large for soccer training (.56; ±.03). Shared variance ranged from 14% to 35%. Conclusions: Practically meaningful differences between dRPE following physical training sessions coupled with low shared variance in all training types and matches suggest that sRPE-B and sRPE-L represent unique sensory inputs in girls’ soccer players. The data provide evidence for the face and construct validity of dRPE as a measure of internal load in this population.

Research has characterised the strength characteristics of elite youth male soccer players, although little is known about female players. This study investigated the influence of age and maturity status on strength characteristics in 157 female soccer players (U16; n=46, U14; n=43, U12; n=38, U10; n=30), recruited from three elite female soccer academies. Linear mixed models were used to determine the difference by age or maturation. Peak force (PF) was possibly and likely greater for older age groups, however relative PF was most likely trivial between consecutive age groups. Relative impulse at 100 and 300 ms was very likely greater at U12 than U10, likely and possibly less at U12 than U14, and most likely less and possibly greater at U16 than U14. Relative PF was likely less at Pre peak height velocity (PHV) than Circa and Circa than Post-PHV. Relative Impulse at 100 and 300 ms was most likely lower for Pre-PHV than Circa and Pre-PHV than Post-PHV, and possible greater at Circa than Post-PHV. Age and maturation impact upon PF and impulse, thus practitioners should account for individual maturation status when comparing players. These data provide reference strength data for elite youth female soccer players, which can be used when monitoring player development.

This study compared the influence of match status (drawing, losing, or winning) and possession status (in-possession, out-of-possession, or ball-out-of-play) on the physical and technical characteristics of U14 and U16 elite youth female soccer match-play. Data were collected from 189 female academy players during 45 competitive matches, resulting in 387 match observations. Linear mixed models estimated relative; total distance, high-speed running (≥3.00 m·s−1), very high-speed running (≥4.83 m·s−1), and sprinting (≥5.76 m·s−1) distance according to match status and possession status, and 21 technical variables according to match status. Differences in physical and technical characteristics were observed between and within age-groups, dependent upon match status and possession status. Regardless of match status, both age-groups covered greater distances when the ball was in-play compared to ball-out-of-play (107–130 vs 58–68 m·min−1). U16s covered greater distances when out-of-possession than in-possession, regardless of match status. Whilst U14s covered greater distances out-of-possession when drawing or losing only. Differences in physical and technical characteristics when drawing, losing, or winning, suggest a change in playing style according to match status, likely in an attempt to influence or maintain the score-line. These findings have practical implications for coaching, talent identification and development practices within youth female soccer.

Purpose: Sled towing has been shown to be an effective method to enhance the physical qualities in youth athletes. The aim of this study was to evaluate the impact of a 6-week sled towing intervention on muscular strength, speed and power in elite youth soccer players of differing maturity status. Method: Seventy-three male elite youth soccer players aged 12–18 years (Pre-Peak Height Velocity [PHV] n=25; Circa-PHV n=24; Post-PHV n=24) participated in this study from one professional soccer academy. Sprint assessments (10 and 30 m), countermovement jump and isometric mid-thigh pull were undertaken before (T1) and after (T2) a 6-week intervention. The training intervention consisted of 6 weeks (2 x per week, 10 sprints over 20 m distance) of resisted sled towing (linear progression 10 to 30% of body mass) during the competitive season. Bayesian regression models analysed differences between T1 and T2 within each maturity group. Results: There were minimal changes in strength, speed and power (p=0.35-0.80) for each maturity group across the 6-week intervention. Where there were changes with greater certainty, they are unlikely to represent real effect due to higher regression to the mean (RTM). Conclusion: It appears that a 6-week sled towing training programme with loadings of 10-30% body mass only maintains physical qualities in elite youth soccer players Pre-, Circa-, and Post-PHV. Further research is required to determine the effectiveness of this training method in long-term athletic development programmes.

Multidisciplinary profiling provides coaches with key information to augment their (de)selection decisions. These profiles often encompass objective and subjective data in the form of signs (isolated assessments), samples (contextualised assessments), and subjective expert opinion (SEO). Whilst multiple sources of information are considered by coach’s during their decision-making, research exploring the extent to which objective and subjective multidisciplinary information can classify (de)selection is limited. Multidisciplinary data (physical profiling, match statistics, coach match ratings) was collected on 58 Under-16 (n=20) and Under-18 (n=38) youth male soccer players from a single academy in the United Kingdom. Group-level differences between selected (n=39) and deselected (n=24) players were explored, and binary logistic regression models were created to classify (de)selection. Analysis revealed a significant difference between selected and deselected players for match ratings (p<0.0001), 505 left foot (p<0.01), frequency of passes, percentage of successful aerial duels, and percentage of accurate crosses (p<0.05). A classification model containing signs, samples, and SEO data demonstrated the best model fit (AIC = 72.63), the highest discriminatory power (AUC = 0.79), and classified players with the greatest accuracy (78%) for (de)selection purposes. The use of signs, samples, and SEO can support (de)selection decisions but fails to fully represent the complexity of the (de)selection process.

Youth male soccer is more competitive than ever as clubs strive to recruit, develop, and produce future elite soccer players. Within youth soccer academies, it is important to recognise that, talent development (TD) and (de)selection are on-going and complex multidisciplinary processes with several challenges. Part 1 of this paper presents three real-world practical challenges including: (1) the ability to differentiate between performance and potential, (2) understanding and alignment to develop talented players, and (3) decision-making processes and (de)selection of players. The paper then presents a possible solution to these challenges demonstrated through the application of a multidisciplinary profiling tool created and utilised within a youth male soccer academy in the UK (Part 2). Finally, Part 3 of the paper identifies the applied challenges associated with implementing such a tool within a TD environment and provides possible solutions for effective implementation. The creation and implementation of the multidisciplinary athlete profiling tool can facilitate TD, and support (de)selection decisions. The solutions provided may serve as principles that can be flexibly implemented across a variety of sports and environments to augment TD and (de)selection processes.

Female football is one of the largest growing sports in the world; yet there is comparatively little research exploring female football talent development environments (TDEs). To develop understanding of TDEs, we explored and compared players’, parents’ and coaches’ perspectives of TDEs, and provide suggestions regarding opportunities for development. Using a cross-sectional design, we surveyed–using the Talent Development Environment Questionnaire-5 (TDEQ-5) − 3217 participants (players n = 1456; parents n = 1432; staff n = 329) from 30 English female football TDEs. Descriptive subscale analysis revealed largely positive perceptions of TDEs (>4/6 of each subscale). Coaches had more positive perceptions of the TDEs than players and parents in all TDEQ-5 subscales, except for the alignment of expectations subscale where coaches had the least positive perception. Significant differences between players, coaches, and parents (p ≤ 0.001) were evident across the support network (coaches most positive, then parents, then players) and alignment of expectations (parents most positive, then players, then coaches) subscales. Based on lowest scoring items from players, coaches and parents, we themed key opportunities for development under (1) achievement-related communication, (2) success planning, and (3) coping skills. Findings can provide direction to national policy makers and inform coach and parent education initiatives.

OBJECTIVES: To (i) quantify the differences in locomotor and technical characteristics between different drill categories in female soccer and (ii) explore the training drill distributions between different standards of competition. METHODS: Technical (ball touches, ball releases, high-speed ball releases) and locomotor data (total distance, high-speed running distance [>5.29 m∙s-1]) were collected using foot-mounted inertial measurement units from 458 female soccer players from three Women's Super League (WSL; n = 76 players), eight Women's Championship (WC; n = 217) and eight WSL Academy (WSLA; n = 165) teams over a 28-week period. Data were analysed using general linear mixed effects. RESULTS: Across all standards, the largest proportion of time was spent in technical (TEC) (WSL = 38%, WC = 28%, WSLA = 29%) and small-sided extensive games (SSGe) (WSL = 20%, WC = 31%, WSLA = 30%) drills. WSL completed more TEC and tactical (TAC) training whilst WC and WSLA players completed more SSGe and possession (POS) drills. Technical drills elicited the highest number of touches, releases and the highest total distance and high-speed activity. Position-specific drills elicited the lowest number of touches and releases and the lowest total distance. When the technical and locomotor demand of each drill were made relative to time, there were limited differences between drills, suggesting drill duration was the main moderating factor. CONCLUSION: Findings provide novel understanding of the technical and locomotor demands of different drill categories in female soccer. These results can be used by coaches and practitioners to inform training session design.

The increased growth and professionalism of women’s football has led to an increased investment in talent identification (ID) and development of players from a young age. Governing bodies are now investing in talent ID and development environments such as academies, which are starting for girls as young as 10-years old, and which are aligned with similar academy structures that are in place in the boy’s and men’s pathway. Talent ID in women’s football has traditionally been based on viewing players in a trial game or training session environment, whereby the players aim to impress coaches. This approach is not informed by scientific evidence, but rather coaches’ subjective preconceived notion of the ideal player, which, when used in isolation, may result in repetitive misjudgements and limited consistency. However, in recent years there has been an increased amount of research exploring talent ID and development in the women’s game. In this chapter, we provide an overview of existing research, case study examples of talent ID challenges and recommendations for talent ID and development practices.

This review aimed to (1) systematically review the scientific literature evaluating the match-play characteristics of women's soccer, (2) determine the methods adopted to quantify match-play characteristics of women's soccer, and (3) present the physical, technical and tactical characteristics of women's soccer match-play across age-groups, playing standards and playing positions. A systematic search of electronic databases was conducted in May 2021; keywords relating to the population, soccer and match-play characteristics were used. Studies which quantified physical, technical or tactical performance of women's soccer players during match-play were included. Excluded studies included adapted match-play formats and training studies. Sixty-nine studies met the eligibility criteria. Studies predominantly quantified match-play characteristics of senior international (n = 27) and domestic (n = 30) women's soccer match-play, with only seven studies reporting youth match-play characteristics. Physical (n = 47), technical (n = 26) and tactical characteristics (n = 2) were reported as whole-match (n = 65), half-match (n = 21), segmental (n = 17) or peak (n = 8) characteristics. Beyond age-groups, playing standard, and playing position, fourteen studies quantified the impact of contextual factors, such as environment or match outcome, on match-play characteristics. Distance was the most commonly reported variable (n = 43), as outfield women's soccer players covered a total distance of 5480-11160 m during match-play. This systematic review highlights that physical match-performance increases between age-groups and playing standards, and differs between playing positions. However, further research is warranted to understand potential differences in technical and tactical match-performance. Coaches and practitioners can use the evidence presented within this review to inform population-specific practices, however, they should be mindful of important methodological limitations within the literature (e.g. inconsistent velocity and acceleration/deceleration thresholds). Future research should attempt to integrate physical, technical and tactical characteristics as opposed to quantifying characteristics in isolation, to gain a deeper and more holistic insight into match-performance.

The aim was to assess concurrent validity and test-retest reliability of spatiotemporal gait parameters from a thoracic placed inertial measurement unit (IMU) in lab- (Phase One) and field-based (Phase Two) conditions. Spatiotemporal gait parameters were compared (target speeds 3, 5 and 7.5 m·s-1) between a 100-Hz IMU and an optical measurement system (OptoJump Next, 1000 Hz) in 14 trained individuals (Phase One). Additionally, 29 English Premier League football players performed weekly 3x60-m runs (5 m·s-1; observations =1227; Phase Two). Mixed effects modelling assessed the effect of speed on agreement between systems (Phase One), and test-retest reliability (Phase Two). IMU step time showed strong agreement (<0.3%) regardless of individual or running speed. Direction of mean biases up to 40 ms for contact and flight time depended on the running speed and individual. Step time, length and frequency were most reliable (Coefficient of variation = 1.3-1.4%) but confounded by running speed. Step time, length and frequency derived from a thoracic-placed IMU can be used confidently. Contact time could be used if bias is corrected for each individual. To optimise test-retest reliability, a minimum running distance of 40 m is needed to ensure 10 constant-speed steps are gathered.

Rugby League (RL) is an intermittent, collision, invasion game, played internationally at professional, semi-professional and amateur level. The physiological attributes required for RL performance include, aerobic and anaerobic power, speed, acceleration, momentum, change of direction speed (CODS), strength, power and technical skill. Professional clubs operating in the Super League, develop academy players, as a method of talent development. However, not all players make the transition to senior, professional status, frequently required to leave this environment and participate at the semi-professional level. This study sought to better understand the physiological differences between these two levels, affording a better understanding of the career transition faced by academy graduates. The variables of examination were unilateral leg strength, strength symmetry, linear and change of direction speed. It was hypothesised that there would be significant differences between all variables. Rugby league players (n = 50), recruited from three different clubs, were used to investigate the physiological differences in unilateral leg strength and speed, both linear and COD. Tests of unilateral leg strength (rear foot elevated split squat 5RM, Helme et al, ePUB) and speed (20m sprint, modified 5-0-5 test) were separated by 48 hours. A magnitude based decision approach was used to determine between group differences in all variables measured. Semi-professional players were significantly heavier (+7kg, p =0.03, possibly moderate difference) than academy players, but there was no difference in height. No significant differences between groups in unilateral leg strength, either in absolute load or relative to body mass, nor was there any difference in strength symmetry. Analysis of linear sprint speed identified no differences between academy and semi-professional players between 0 and 10m, of a 20m sprint, however, between 10and 20m academy players had a possibly moderately higher mean velocity (7.57m/s vs 7.7m/s, p =0.35). Despite the difference in body mass no significant differences in momentum was observed. There were no significant differences between either group for change of direction speed or change of direction deficit. Academy and Semi-professional players exhibit comparable qualities with respect to unilateral leg strength, speed and change of direction ability. Such findings suggest that a career transition from academy to semi-professional Rugby League is an appropriate step, from a physiological perspective. However anthropometrically, the differences in body mass between groups suggests that such progression may not be so advantageous. Whilst both groups have equitable abilities, semi-professional players can perform these tasks at a significantly larger body mass, which is beneficial in collision sports. It should be concluded then, that in the transition to exit academy rugby league environments players should be focused on a strategy to simultaneously develop speed and change of direction ability, whilst accumulating greater lean body mass.

Rugby League (RL) is an intermittent, high intensity, collision sport characterised by frequent accelerations and changes of direction (Gabbett et al., 2008). Leg strength has been associated with improved performance in both linear and change of direction speed (CODS) (Bret et al., 2002, Wisløff et al., 2004, Cronin and Hansen, 2005, McBride et al., 2009). Previous research has used bilateral methods of investigating this association, yet few studies have taken a unilateral approach to strength assessment. The aim of this study was to investigate the relationships between unilateral leg strength speed, momentum, change of direction speed and change of direction deficit, in RL players. Further understanding the interaction to different forms of strength and performance measures may better enable practitioners to prepare their athletes. It was hypothesized that increased leg strength would positive influence performance in sprint and CODS measures. With institutional ethical approval testing was conducted at the respective facilities of three participating Rugby League clubs (n = 50). Physiological testing was separated into two sessions the first being speed and change of direction assessment and the second collection of strength data. CODS was measured using the modified 5-0-5 test, speed was tested using a 20m linear sprint from a standing start. For both tests three trials were performed and the best result used for analysis. Unilateral leg strength was measured using the rear foot elevated split squat (RFESS) 5RM (Helme et al, under review). Strength data was calculated in both absolute and relative terms, linear speed was analysed at both 10m and 20m for time, mean velocity and mean momentum for each 10m section. CODS was analysed for time and also for change of direction deficit, (Nimphius et al., 2016). The mean absolute load achieved in the RFESS 5RM was 88.92 ±12.59kg, when expressed relative to body mass was 1.01 ±0.17kg/kg. Possibly to likely small negative associations were found to both change of direction times and change of direction deficits. Possibly small positive associations were observed between momentum and velocity, for the 10-20m section, but not for 0-10m. No correlations reached the alpha level of significance (p = <0.05) for absolute strength. A most likely or almost certain moderate negative relationship was found between CODS and relative leg strength (p= <0.05) and a likely moderate positive relationship to linear mean velocity between 10 and 20m. Almost certainly moderate (10-20m) or large (0-10m) negative relationships were observed with momentum in a linear sprint (p = >0.05). The data from this study suggests that absolute unilateral leg strength is not significantly related to sprinting or CODS performance. However, increasing relative unilateral leg strength is positively associated with increased change of direction speed and velocity, specifically between 10m and 20m. Furthermore, almost certainly large negative correlations were found between relative leg strength and momentum, which is at odds with the other findings of this study. Baker and Newton (2008) identified momentum as a significant contributor to performance in RL, particularly in winning collisions, which are in turn, essential for successful match outcomes. Practitioners may consider the use of relative unilateral leg strength to better understand the development of velocity and CODS in their athletes. This should be taken with caution though, as further investigation is required to better understand the interaction between relative strength and momentum.

The purpose of the study was to determine the unilateral nature of the rear foot elevated split squat (RFESS). Specifically, the production of force by the rear leg was examined to better understand its role, if any, toward successful completion of the exercise. Male volunteers were recruited, (n = 26, age = 23.8 ±4.6 years, mass = 88.1 ±10.7kg, height = 1.79±0.1m), who were recreationally trained and engaged in a structured strength and conditioning program including both bilateral and unilateral exercise and had at least two years supervised training experience. Subjects participated in an incremental five repetition maximum protocol, following familiarisation. Kinetic data was recorded via two independent force plates, one integral to the floor and the second mounted on top of solid weightlifting blocks. Kinematic data was captured through three-dimensional motion analysis. A total of 715 repetitions were analysed, the mean contribution of the lead foot to total vertical force production was 84.36 ±3.6%. An almost certainly small positive correlation (rho = 0.25, CI 0.18, 0.33), was found between percentage of force produced by the lead foot, with increasing exercise intensity. A most likely trivial, non-significant correlation (rho = -0.01, CI -0.09,0.06) with rear foot force production, representing the mass of the rear leg. Data from this study does not indicate that the rear foot contributes to the kinetic demands of the exercise and therefore suggests that the RFESS is a valid unilateral exercise.

Objectives The aim of this study was to analyse the relationship between unilateral leg strength, associated asymmetries and the injuries suffered by sub-elite Rugby League (RL) players in one competitive season. Design A prospective cohort design was used. Method Unilateral leg strength was measured using the rear foot elevated split squat five repetition maximum test. Injuries were recorded using the Orchard classification system and were used to quantify relative risk (RR), mean severity, burden, player availability and survival time. Results No measures of leg strength were related to RR, relative leg strength was found to have a significant, but not meaningful correlation with total time lost to lower body injury, lower body injury burden and lower body injury survival time. Conclusions The data from the current study indicates a possible positive effect of increasing relative leg strength for injury outcomes in sub-elite RL players. This supports a heuristic that multi-joint lower body strength training for RL players has a potential dual effect of enhancing physical performance and reducing injury time loss, with minimal risk of harm.

SYNOPSIS: This Viewpoint explores the “professionalization mismatch” in women’s football (soccer)—the disparity between rising demands and insufficient resources despite increasing demands on professional athletes. Anterior cruciate ligament (ACL) injury incidence has remained steady over the past 2 decades. ACL injuries are severe injuries for players, often leading to short-term deficits in performance and long-term health issues. Our attempt to conduct a systematic review on ACL injury risk reduction strategies in professional women’s football revealed a significant knowledge gap, highlighting the challenges of conducting rigorous research in this context. We propose steps to address these gaps, including evaluating current practices, conducting qualitative research, adopting open science practices, and facilitating interdisciplinary collaboration injury risk reduction programs to the growing demands of professional women football players. Collaborative research can support developing and implementing tailored ACL injury risk reduction strategies to improve players’ health and performance in professional women’s football. J Orthop Sports Phys Ther 2025;55(6):386-389. Epub 21 April 2025. doi:10.2519/jospt.2025.12926

In recent years there has been an exponential rise in the professionalism and success of female sports. Practitioners (e.g., sport science professionals) aim to apply evidence-informed approaches to optimise athlete performance and well-being. Evidence-informed practices should be derived from research literature. Given the lack of research on elite female athletes, this is challenging at present. This limits the ability to adopt an evidence-informed approach when working in female sports, and as such, we are likely failing to maximize the performance potential of female athletes. This article discusses the challenges of applying an evidence base derived from male athletes to female athletes. A conceptual framework is presented, which depicts the need to question the current (male) evidence base due to the differences of the "female athlete" and the "female sporting environment," which pose a number of challenges for practitioners working in the field. Until a comparable applied sport science research evidence base is established in female athletes, evidence-informed approaches will remain a challenge for those working in female sport.

The purpose of this study was to examine the validity and reliability of the Rear Foot Elevated Split Squat (RFESS) five repetition maximum (5RM) test as a field method for measuring unilateral leg strength symmetry. As a validated method of testing symmetry, the RFESS 5RM may be used by Strength and Conditioning coaches and sports medicine staff to measure the presence of imbalances with minimal equipment and time. 26 subjects (age = 23.8 ±4.6 years, mass = 88.1 ±10.7kg, height = 1.79±0.1m) with a minimum two years strength and conditioning experience were recruited. Following a familiarization session, subjects performed an incremental five repetition maximum (5RM) protocol on both legs, on two occasions where 3D motion and force data were collected. Moderate reliability of bar load symmetry was found between test and re-test conditions correlation (ICC = 0.73, 0.33-0.91) with no proportional bias between sessions. Validation of the exercise was analyzed using a correlation between asymmetries in mean set vertical ground reaction forces (vGRF) of the lead foot during the concentric phase, with bar load. When all maximal trials, from both test conditions, were analyzed, a most likely large positive correlation (0.57, 0.30 to 0.76) were found for mean set concentric lead foot vGRF. When a threshold level of load symmetry (96.54% - 103.46%) was applied, a most likely large positive correlation (r = 0.59, 0.14-0.84) between symmetry in lead foot vGRF was found in subjects who exceeded this limit. Conversely, analysis of subjects within the threshold produced unclear correlations. Findings of this study suggest the RFESS is a valid and reliable measure of unilateral leg strength symmetry. Practitioners are recommended to use this exercise to investigate the strength symmetry of athletes, but are guided to note that a threshold level of symmetry (96.54% - 103.46%) may be required to have been exceeded to indicate a true difference in vGRF production.

The rear foot elevated split squat (RFESS) is a multi-joint, unilateral resistance exercise, commonly used in strength and conditioning McCurdy (2017). McCurdy, Langford et al. (2004) and McCurdy and Langford (2005) have previously reported the RFESS as a reliable measure of unilateral leg strength (1RM ICC, 0.97- 0.99). To further enhance the proposed frequency of use and reliability as both a single and multiple repetition test of leg strength, it is pertinent to quantify the kinetic and kinematic characteristics of the exercise. No study, to date, has yet analysed the intra-set differences in kinetic and kinematic parameters, in a multi-repetition test of leg strength. The aim of this study was to firstly quantify the kinetic and kinematic characteristics of the RFESS 5RM test protocol. Secondly to profile the intra-set differences between repetitions. 26 volunteers were recruited, with institutional ethical approval (age = 23.8 ±4.6 years, mass = 88.1 ±10.7kg, height = 1.79±0.1m), all subjects were engaged in a structured strength and conditioning program. Participants were required to undergo an incremental loading test until maximal load was achieved. Kinetic data was collected from the front and rear foot through two independent Kistler 9827C force plates at 1000Hz (Kistler Group, Winterthur, Switzerland), as depicted in figure 1. Kinematic data was captured through Qualysis Track Manager System at 250Hz (Qualysis AB, Gothenburg, Sweden) using 10 cameras (six ceiling mounted and four, floor mounted).Data was exported to a bespoke R code for this project. Magnitude based inferences were made on intra-set differences between repetitions for each of the kinetic and kinematic variables. The mean load lifted was 84kg ±16.8kg (0.96 ±0.18 kg/kg). The mean vertical displacement of the bar was 0.38 ± 0.06m, mean concentric velocity was 0.32 ±0.05m/s and peak concentric velocity was 0.49 ±0.11m/s. The mean vertical ground reaction force (vGRF) of the lead foot was 1432.54±200.87N, (1.66 ±0.20BW). The lead foot produced 83.53±4.03% of total vGRF There were unclear differences in all kinetic variables between all repetitions, except for peak (vGRF) of the lead foot only (1.90±0.28BW) of Repetition 5, which was very likely larger. Repetitions 1 and 2 were likely to very likely to have higher mean concentric velocities (MCV) than repetitions 4 and 5. The RFESS 5RM produces mean and peak concentric vGRF of 1.66±0.20 BW and 1.84±0.24BW, which approximately equals the values reported by (Ebben and Jensen, 2002) for a bilateral squat. The inconsistent inferential findings across the set suggest that the final repetition may be different to repetitions 1-4, generating the highest peak force, largest vertical displacement and slowest MCV. Such findings indicate that repetition 5 represents the maximal effort of that set and the maximal protocol. The RFESS 5RM is valid and reliable method of measuring unilateral leg strength. A multi-repetition protocol can be used to determine maximal strength, yet intra-set differences may not exist prior to completion of the final repetition. Practitioners should consider this information when evaluating the efforts of athletes during this exercise.

The rear foot elevated split squat (RFESS) is a multi-joint, unilateral resistance exercise, commonly used in strength and conditioning (McCurdy, 2017). McCurdy, Langford et al. (2004) and McCurdy and Langford (2005) have previously reported the RFESS as a reliable measure of unilateral leg strength (1RM ICC, 0.97- 0.99). To further enhance the proposed frequency of use and reliability as both a single and multiple repetition test of leg strength, it is pertinent to quantify the kinetic and kinematic characteristics of the exercise. No study, to date, has yet analysed the intra-set differences in kinetic and kinematic parameters, in a multi-repetition test of leg strength. The aim of this study was to firstly quantify the kinetic and kinematic characteristics of the RFESS 5RM test protocol. Secondly to profile the intra-set differences between repetitions. METHODS 26 volunteers were recruited, with institutional ethical approval (age = 23.8 ±4.6 years, mass = 88.1 ±10.7kg, height = 1.79±0.1m), all subjects were engaged in a structured strength and conditioning program. Participants were required to undergo an incremental loading test until maximal load was achieved. Kinetic data was collected from the front and rear foot through two independent Kistler 9827C force plates at 1000Hz (Kistler Group, Winterthur, Switzerland), as depicted in figure 1. Kinematic data was captured through Qualysis Track Manager System at 250Hz (Qualysis AB, Gothenburg, Sweden) using 10 cameras (six ceiling mounted and four, floor mounted).Data was exported to a bespoke R code for this project. Magnitude based inferences were made on intra-set differences between repetitions for each of the kinetic and kinematic variables. RESULTS The mean load lifted was 84kg ±16.8kg (0.96 ±0.18 kg/kg). The mean vertical displacement of the bar was 0.38 ± 0.06m, mean concentric velocity was 0.32 ±0.05m/s and peak concentric velocity was 0.49 ±0.11m/s. The mean vertical ground reaction force (vGRF) of the lead foot was 1432.54±200.87N, (1.66 ±0.20BW). The lead foot produced 83.53±4.03% of total vGRF There were unclear differences in all kinetic variables between all repetitions, except for peak (vGRF) of the lead foot only (1.90±0.28BW) of Repetition 5, which was very likely larger. Repetitions 1 and 2 were likely to very likely to have higher mean concentric velocities (MCV) than repetitions 4 and 5. Figure 1: Data collection procedures for the RFESS 5RM protocol DISCUSSION The RFESS 5RM produces mean and peak concentric vGRF of 1.66±0.20 BW and 1.84±0.24BW, which approximately equals the values reported by (Ebben and Jensen, 2002) for a bilateral squat. The inconsistent inferential findings across the set suggest that the final repetition may be different to repetitions 1-4, generating the highest peak force, largest vertical displacement and slowest MCV. Such findings indicate that repetition 5 represents the maximal effort of that set and the maximal protocol. CONCLUSION The RFESS 5RM is valid and reliable method of measuring unilateral leg strength. A multi-repetition protocol can be used to determine maximal strength, yet intra-set differences may not exist prior to completion of the final repetition

The purpose of this study was to examine the Rear foot elevated split squat (RFESS) five repetition maximum test as a valid and reliable field method for measuring unilateral leg strength symmetry. With institutional ethical approval, 26 subjects (age = 23.8 ±4.6 years, mass = 88.1 ±10.7kg, height = 1.79±0.1m) with a minimum two years strength and conditioning experience were recruited. Following a familiarisation, session subjects performed an incremental 5 repetition maximum (RM) protocol on both legs, on two occasions where 3D motion and force data were collected. excellent reliability was found (ICC = 0.93 CL 0.88-0.96) in the load achieved between tests (mean load =0.96 ±0.18 kg/kg). Moderate reliability of bar load symmetry was found between test and re-test conditions correlation (ICC = 0.73, 0.33-0.91) with no proportional bias between sessions. Validation of the exercise was measured using a Pearson correlation between asymmetries in vertical ground reaction forces of the lead foot and bar load. When all maximal trials, from both test conditions, were analysed, a most likely large positive correlation (0.57, 0.30 to 0.76) were found for mean lead foot vGRF. When a threshold level of load symmetry (96.54% - 103.46%) was applied, a most likely large positive correlation (r = 0.59, 0.14-0.84) between symmetry in lead foot vGRF was found in subjects who exceeded this limit. Findings of this study suggest the RFESS is a valid and reliable measure of unilateral leg strength symmetry. Practitioners are recommended to use this exercise to investigate the strength symmetry of athletes, but are guided to note that a threshold level of symmetry (96.54% - 103.46%) may be required to have been exceeded to indicate a true difference in vGRF production

Ranking enables coaches, sporting authorities, and pundits to determine the relative performance of individual athletes and teams in comparison to their peers. While ranking is relatively straightforward in sports that employ traditional leagues, it is more difficult in sports where competition is fragmented (e.g. athletics, boxing, etc.), with not all competitors competing against each other. In such situations, complex points systems are often employed to rank athletes. However, these systems have the inherent weakness that they frequently rely on subjective assessments in order to gauge the calibre of the competitors involved. Here we show how two Internet derived algorithms, the PageRank (PR) and user preference (UP) algorithms, when utilised with a simple ‘who beat who’ matrix, can be used to accurately rank track athletes, avoiding the need for subjective assessment. We applied the PR and UP algorithms to the 2015 IAAF Diamond League men’s 100m competition and compared their performance with the Keener, Colley and Massey ranking algorithms. The top five places computed by the PR and UP algorithms, and the Diamond League ‘2016’ points system were all identical, with the Kendall’s tau distance between the PR standings and ‘2016’ points system standings being just 15, indicating that only 5.9% of pairs differed in their order between these two lists. By comparison, the UP and ‘2016’ standings displayed a less strong relationship, with a tau distance of 95, indicating that 37.6% of the pairs differed in their order. When compared with the standings produced using the Keener, Colley and Massey algorithms, the PR standings appeared to be closest to the Keener standings (tau distance = 67, 26.5% pair order disagreement), whereas the UP standings were more similar to the Colley and Massey standings, with the tau distances between these ranking lists being only 48 (19.0% pair order disagreement) and 59 (23.3% pair order disagreement) respectively. In particular, the UP algorithm ranked ‘one-off’ victors more highly than the PR algorithm, suggesting that the UP algorithm captures alternative characteristics to the PR algorithm, which may more suitable for predicting future performance in say knockout tournaments, rather than for use in competitions such as the Diamond League. As such, these Internet derived algorithms appear to have considerable potential for objectively assessing the relative performance of track athletes, without the need for complicated points equivalence tables. Importantly, because both algorithms utilise a ‘who beat who’ model, they automatically adjust for the strength of the competition, thus avoiding the need for subjective decision making.

The purpose of this study was to (a) provide comparative isometric midthigh pull (IMTP) force-time characteristics for elite youth soccer players and (b) determine the effect of age and maturation on IMTP force-time characteristics. Elite male youth soccer players (U12 n = 51; U13 n = 54; U14 n = 56; U15 n = 45; U16 n = 39; and U18 n = 48) across 3 maturity offset groups (Pre n = 117; circa n = 84; and Post–peak height velocity n = 92) performed 2 maximal IMTP trials on a portable force platform (1,000 Hz). Absolute and relative values for peak force (PF) and impulse over 100 and 300 ms were analyzed. A full Bayesian regression model was used to provide probable differences similar to that of a frequentist p value. Advanced age and maturation resulted in superior IMTP force-time characteristics. Peak force demonstrated high probabilities of a difference between all consecutive age groups (p > 0.95). For absolute and relative impulse (100 and 300 ms), only 2 consecutive age groups (U14–15's and U16–18's) demonstrated high probabilities of a difference (p > 0.95) with large effects (d = 0.59–0.93). There were high probable differences between all maturity offset groups for PF and impulse with medium to large effects (d = 0.56–3.80). These were also reduced when expressed relative to body mass (relative PF and relative impulse). This study provides comparative IMTP force-time characteristics of elite male youth soccer players. Practitioners should consider individual maturation status when comparing players given the impact this has on force expression.

Fitness testing is common practice within youth athletes. However, the interpretation of fitness data often occurs within chronological annual-age categories, resulting in athletes being (dis)advantaged due to age or maturity discrepancies. Instead, evaluating fitness performance against rolling averages may be more appropriate. This article presents a novel method for analyzing fitness testing data in youth athletes using Z-scores according to rolling averages for both chronological age and maturity status. This analysis technique allows the dual ability to interpret youth fitness performance according to age and maturation, enhancing accuracy of data interpretation for talent identification, development and strength and conditioning programming.

Talent identification of young soccer players is a significant consideration for elite youth soccer organisations, with decisions on players often being made based on the subjective expert opinion of scouts and coaches. Previous research has suggested that scouts and coaches purportedly consider a multitude of factors before arriving at their decisions. However, to date, limited research exists regarding how coaches evaluate player potential within such organisations and how the consideration of further data may influence such evaluations of a player's future potential. Therefore, the aim of this study was to present ratings of perceived potential in an elite youth soccer academy and explore the relationships between a player's perceived potential, athleticism, and perceived level of current match performance. Using 181 player observations, findings demonstrated that ratings of players’ perceived potential decreased within older age groups and were the lowest in the senior academy age group (U18). Furthermore, a mixed effects ordinal regression model suggested that coaches’ perceptions of a player's future potential demonstrated strong relationships with current match performance and athleticism. Increases in a player's mean match rating significantly increased the odds of them being perceived to have higher potential and increases in athleticism also demonstrated a positive relationship with increased perceptions of potential. The findings have implications for youth soccer organisations, providing insight into the distribution of ratings of potential within an elite youth soccer academy, and demonstrating that further data (match performance and athleticism) is related to, and may influence, coaches’ perceptions of player potential.

This study aimed to investigate the incidence, severity, and burden of injury in English elite youth female soccer players. Qualified therapists at six English girls' academies prospectively recorded all injuries that required medical attention or caused time loss for matches and training in 375 elite youth female soccer players (under-10 , U12, U14 and U16) during the 2019/2020 season. One hundred- and eleven time-loss injuries (52 from training, 59 from matches) were sustained, resulting in 1,946 days absent (779 days from training injuries, 1,167 days from match injuries) from soccer activities. The injury incidence for matches (9.3/1000 hours, 95% CIs: 7.2-11.9) was significantly greater than training (1.1/1000 hours, 95% CIs: 0.9-1.5, p<0.001). Additionally, the injury burden for matches (183 days lost/1000 hours, 95% CIs: 142-237) was significantly greater than training (17 days lost/1000 hours, 95% CIs: 13-22, p<0.001). Injury incidence and burden were greatest in the U16 age group, and were found to increase with age. Whilst injury incidence and burden are greater in matches than training, a large proportion of preventable injuries, soft-tissue and non-contact in nature, were sustained in training. Findings provide comparative data for elite youth female soccer players.

The increased growth and professionalism of women’s football have led to an increased investment in talent identification and development of players from a young age. Governing bodies are now investing in talent identification and development environments such as academies, which are starting for girls as young as 10 years, and which are aligned with similar academy structures that are in place in the boys’ and men’s pathway. Talent identification in women’s football has traditionally been based on viewing players in a trial game or training session environment, whereby the players aim to impress coaches. This approach is not informed by scientific evidence, but rather coaches’ subjective preconceived notion of the ideal player, which, when used in isolation, may result in repetitive misjudgements and limited consistency. However, in recent years there has been an increased amount of research exploring talent identification and development in the women’s game. In this chapter, an overview of existing research is provided, as well as case study examples of talent-identification challenges and recommendations for talent identification and development practices.

The ability of sporting organisations to identify and develop athletic talent into the sporting superstars of tomorrow has significantly grown and intensified in recent years. This chapter focuses on the talent identification step of this process. Talent identification is defined as ‘recognising participants with the potential at an earlier age to become elite performers in the future’ with multiple talent identification systems employed across the world. Talent identification processes can be informed by coach recommendations, training/competition observations and fitness assessments, although a collaborative approach is recommended. Although coaches believe they can identify talent, a multitude of research examining talent has emerged over the last two decades exploring the phenomenon of talent. This chapter reviews some of this research, with a focus on the physical qualities and methods that may be used as talent identification tools. The chapter then presents numerous problems related to talent identification within young athletes including the performance vs potential debate, early identification = early specialisation, annual age grouping and maturity variability, and unidimensional and cross-sectional approaches to talent identification. Numerous potential solutions to help practitioners optimise their talent identification programmes in young athletes are then discussed.

The purpose of this study was to quantify the technical characteristics of U14 and U16 elite youth female soccer match-play and compare position-specific differences between and within these age groups. A total of 449 match observations from 45 matches were undertaken on 189 players representing Regional Talent Centres in The Football Association’s Girls’ England Talent Pathway league. Linear mixed modelling determined position-specific differences for 24 technical and 4 possession-based variables. Results showed similar team possession-based characteristics at both age groups. Interceptions (U14 = 4.6 ± 0.3, U16 = 3.9 ± 0.3) and tackles (U14 = 4.2 ± 0.3, U16 = 3.2 ± 0.3) were the most common defensive actions. Passes were the most common offensive action (U14 = 21.8 ± 1.8, U16 = 25.1 ± 1.9). In possession, U14 central players performed more actions than wide players, whilst actions were more evenly distributed amongst positions at U16, suggesting a variation in playing style between age groups. Technical performances of players were position-dependent, and differences in offensive and defensive variables were observed between age groups across all positions. These findings may assist practitioners in informing specific coaching practice, training programme design or talent identification processes within this population.

This study quantified whole and peak physical characteristics of Under (U)14 and U16 elite youth female soccer, and compared by position and age-group. Data was collected using 10 Hz GPS units from 431 match observations, during 50 matches involving 201 players (U14 n = 93; U16 n = 108) representing Regional Talent Centres in The Football Association’s Girl’s England Talent Pathway League. Whole match data were reported as absolute and relative; total (TD), high-speed running (HSR; ≥3.46 m·s−1), very high-speed running (VHSR; ≥5.29 m·s−1), and sprinting (SPR; ≥6.26 m·s−1) distance, and maximum velocity. Moving average analysis determined peak data (1–10 minute durations). Linear mixed models established position-specific differences. U16s covered greater; absolute distance at all speeds (small-moderate ESs; p < 0.001); relative VHSR and SPR m·min−1 (small-moderate ESs; p < 0.001); peak TD and HSR m·min−1 (small ESs) across several peak-durations, and VHSR m·min−1 (small ESs; p < 0.001) across all peak-durations compared to U14s. Position-specific differences were observed across all positions between and within both age-groups, identifying whole and peak physical characteristics are age- and position-dependent within elite youth female soccer match-play. Findings may facilitate informed coaching practices and training programme design, talent identification and development processes.

Talent identification (TID) and talent development (TD) continue to receive significant investment from team sports organisations, highlighting their importance in attempting to identify potential elite athletes. Accompanying this continual pursuit to unearth future talent is an ever- increasing body of research aiming to provide solutions and strategies to optimise TID and TD processes. Therefore, the aim of this review is to provide a summary and critical synthesis of the methodological approaches applied to TID in team sports and present considerations for future TID research. Specifically, this review highlights three key areas for consideration: (1) the timespan of the research design; (2) the use of monodisciplinary or multidisciplinary variables; and (3) the fidelity of the methodological approaches to the assessment of talent. The review highlights the benefits of longitudinal, multidisciplinary, and ecologically valid research designs for TID within team sports.

Purpose: This study aimed to establish age-specific velocity thresholds for Under (U)14 and U16 elite youth female soccer players. Methods: Data was collected using 10 Hz GPS units during 50 matches from 187 players (U14 n = 89; U16 n = 98). Spectral clustering identified velocity thresholds for high-speed running (HSR), very high-speed running (VHSR), and sprinting (SPR), for 699 half-match observations (U14 n = 369; U16 n = 330). Linear mixed modelling determined youth (U14 and U16) and age-group (U14 or U16) velocity thresholds, and compared distances covered between these and existing senior thresholds. The effect of playing position and playing half on velocity thresholds was also quantified. Results: Youth velocity thresholds of HSR (≥3.00 m·s−1), VHSR (≥4.83 m·s−1), and SPR (≥5.76 m·s−1) were estimated from the model. Age-group and playing position influenced velocity thresholds but playing half did not. Adoption of youth and age-group velocity thresholds resulted in greater distance covered at HSR, VHSR, and SPR (p < 0.001; moderate-large effect size [ES] = 0.86–1.97) compared to senior thresholds. Both age-groups covered similar distances (trivial-small ESs = 0.002–0.23) when adopting youth and age-group velocity thresholds. Conclusion: These youth thresholds provide an alternative to arbitrary velocity thresholds within the literature, and thresholds derived from senior players or other populations, to inform appropriate quantification and interpretation of physical data within this population.

The purpose of this study was to investigate the influence of maturity status on the physical characteristics of youth female soccer players. One hundred fifty-seven players from 3 elite soccer academies in England completed assessments of anthropometry, strength (isometric midthigh pull), lower-body power (countermovement jump [CMJ]), aerobic capacity (Yo-Yo intermittent recovery test level 1), change of direction (CoD: 505-left/right), and speed (10 and 30 m). Each player was classified into 1 of 6 maturity groups based on their estimated years from peak height velocity (YPHV). Magnitude-based inferences were used to assess for the practical significance between consecutive groups. Speed, CoD time, CMJ, and aerobic capacity were all possibly most likely better in more mature players. However, there was a likely difference in relative peak force between maturity groups −0.5 YPHV (27.13 ± 4.24 N·Kg−1) and 0.5 YPHV (24.62 ± 3.70 N·Kg−1), which was associated with a likely difference in 10-m sprint time (−0.5 YPHV: 2.00 ± 0.12 vs. 0.5 YPHV 2.08 ± 0.16 seconds) and unclear changes in CMJ and CoD time. Findings provide novel comparative data for this cohort relative to maturity status and can be used by strength and conditioning coaches to inform the design of training programs for youth female soccer players. Strength and conditioning coaches should be aware that youth female soccer players may experience a decrease in relative strength around peak height velocity, which may impact upon the speed, CoD time, and CMJ of players.

This study evaluated the anthropometric, speed and endurance characteristics of English academy soccer players, comparing players who obtained a ‘professional’ contract at 18 years old with those that did not (‘academy’); 443 male academy soccer players from an English professional club undertook anthropometric (height and body mass), speed (10 and 20 m sprint) and endurance (Yo-Yo intermittent endurance test level 2 [Yo-Yo]) assessments between 2005 and 2012. Significant improvements with age were found for speed and endurance at each annual age group up until U18 age category. Significant differences were only observed between ‘professional’ and ‘academy’ players for 10 m (p = 0.003, η2 = 0.01) and 20 m (p = 0.001, η2 = 0.01) speed at U16 and U18 and Yo-Yo performance (p = 0.001, η2 = 0.12) at U18 age category. Practitioners should use speed and endurance assessments for monitoring physical development of players rather than for talent identification purposes.

The health and wellbeing benefits of taking part in organised sport for children and adolescents have been widely reported (Holt et al., 2017) yet participation levels have declined steadily and globally over the last decade (Eime, et al. 2019). However, most of this research has been conducted outside of Europe and although it is safe to assume certain similarities, there is a need for research to explore youth sport participation trends specifically within Europe to inform youth sport participation initiatives. Therefore, the aim of this study, part of Erasmus’ co-funded project ICOACHKIDS+, was to explore organised youth sport participation rates across Europe. Participation data was collected for 5,565,860 children aged 6–18 years (males=4,456,915; females=1,108,945) across 18 sports and 27 countries. Differences in the participation rates between genders and biannual age categories were investigated using a generalised linear mixed effects model. Overall, youth male sport participation rates (∼80%) are significantly higher than females (∼20%). Sports participation peaks for both males and females between 12–14 years. Participation decreases significantly for boys from 14-to-18 years of age in most sports. Girls’ participation significantly decreases between 14–16 years but increases again between 16–18 years in some sports. Findings suggest that strategies to keep more youth engaged in sport, in particular girls, are needed. It is also recommended that sport policy focuses upon overall participation across sports using a longitudinal track approach, and that further research is needed to understand sport attrition from the perspective of the young person, and across a range of demographic variables

Understanding differences in locomotor and collision characteristics between phases of play can help rugby league coaches develop training prescription. There are no data currently available describing these differences at the elite international level. The aim of our study was to determine the differences in average speed (m∙min−1), high-speed running (>5.5 m∙s−1) per minute and collision frequencies per minute (n∙min−1) between attack and defence during the 2017 Rugby League World Cup (RLWC). Methods: Microtechnology data were collected from 24 male professional rugby league players from the same international squad across six matches of the RLWC. Data were then subject to exclusion criteria and stratified into forwards (n = 9) and backs (n = 7) before being analysed with linear mixed-effects models. Results: When comparing attack with defence, forwards and backs had substantially slower average speeds (effect size [ES]; ±90% confidence limits: −2.31; ±0.31 and −1.17; ±0.25) and substantially greater high-speed distance per minute (1.61; ±0.59 and 4.41; ±1.19). Forwards completed substantially more collisions per minute when defending (2.75; ±0.32) whilst backs completed substantially more when attacking (0.63; ±0.70). There was greater within- and between-player variability for collision frequency (coefficient of variation [CV] range; 25–28%) and high-speed distance (18–33%) per minute when compared to average speed (6–12%). Conclusions: There are distinct differences in locomotor and collision characteristics when attacking and defending during international rugby league match-play, yet the variability of high-speed running and collisions per minute is large. These data may be useful to plan or evaluate training practices.

Objective The aim of this review was to synthesize the current understanding relating to the risks of lower body functional asymmetry with injury in athletic populations. Methods An iterative data mining and sampling approach was used to construct a search phrase from key words, which were used to identify studies within SPORTdiscus, Medline and Academic Search Complete databases. Additional references were sourced from the reference lists of these articles Results After screening, 31 papers were reviewed, from an initial search identifying 302 possible studies. A total of 6228 participants were involved in the studies, of which soccer players were the most observed sporting demographic (n =2171). Of the 31 studies reviewed eight found no statistical association between lower limb asymmetry and injury risk, 10 studies provided partial statistically significant evidence and a further 10 provided statistically significant statistical links. Conclusion Overall moderate to lower quality evidence for functional asymmetry as a risk factor for injury in sport was observed. While the possibility of a relationship between lower limb functional asymmetry and injury risk cannot be ruled out, further higher quality investigations, adopting standardised methodologies, is required.

Background Participation in sport is a popular pastime for children and adolescents that improves their physical health, mental health and motor skills. Musculoskeletal injuries are a relatively common downside of sports participation and can have negative long-term consequences. Injury prevention programmes have demonstrated effectiveness in child and adolescent sports, provided compliance is adequate. However, little is known about the factors which relate to their impact on the wider community and whether the prevention programmes have been adopted and maintained in the long-term. The objective of this review was to assess the current literature on exercise-based injury prevention interventions in child and adolescent sports (aged under 19 years) against the ‘Reach’, ‘Effectiveness’, ‘Adoption’, ‘Implementation’, ‘Maintenance’ (RE-AIM) framework and Consensus of Exercise Reporting Template (CERT), to ascertain level of reporting for the components which relate to external validity. Methods Seven electronic databases; PubMed, Medline, SPORTDiscus, PsycINFO, CINAHL, Scopus and The Cochrane Library, were searched from date of inception to July 2022 using the themes of: ‘Child and Adolescent’, ‘Sport’, ‘Injury’ and ‘Prevention’. Eligibility criteria included: Experimental trial design, exercise-based intervention programmes, primary outcome of injury incidence and participants aged under 19 years. Two reviewers assessed each trial independently against the RE-AIM model dimension items checklist (RE-AIM MDIC) and Consensus on Exercise Reporting Template (CERT) before reaching a consensus on reporting. Results Forty-five unique trials met the eligibility criteria. Mean reporting level for all studies across the whole RE-AIM MDIC was 31% (SD ± 16.2%, Range 7–77%). The domain of ‘effectiveness’ was the most comprehensively reported (60%), followed by ‘implementation’ (48%), ‘reach’ (38%), ‘adoption’ (26%) and ‘maintenance’ (7%). The mean reporting score for the CERT was 50% (SD ± 20.8, range 0–81%). Conclusion Published data on injury prevention in child and adolescent sports is highly focussed on the effectiveness of the intervention, with little consideration given to how it will be adopted and maintained in the long-term. This has led to considerable gaps in knowledge regarding optimal programme implementation, with a lack of data on adoption and maintenance contributing to the gap between research and practice. Future research needs to place greater focus on external validity and consider incorporating the study of implementation and feasibility as part of effectiveness trial design. This approach should provide the data that will help narrow the considerable gap between science and practice.

Objectives Soccer leagues reflect the partial standings of the teams involved after each round of competition. However, the ability of partial league standings to predict end-of-season position has largely been ignored. Here we analyze historical partial standings from English soccer to understand the mathematics underpinning league performance and evaluate the predictive ‘power’ of partial standings. Methods Match data (1995-2017) from the four senior English leagues was analyzed, together with random match scores generated for hypothetical leagues of equivalent size. For each season the partial standings were computed and Kendall’s normalized tau-distance and Spearman r-values determined. Best-fit power-law and logarithmic functions were applied to the respective tau-distance and Spearman curves, with the ‘goodness-of-fit’ assessed using the R2 value. The predictive ability of the partial standings was evaluated by computing the transition probabilities between the standings at rounds 10, 20 and 30 and the final end-of-season standings for the 22 seasons. The impact of reordering match fixtures was also evaluated. Results All four English leagues behaved similarly, irrespective of the teams involved, with the tau-distance conforming closely to a power law (R2>0.80) and the Spearman r-value obeying a logarithmic function (R2>0.87). The randomized leagues also conformed to a power-law, but had a different shape. In the English leagues, team position relative to end-of-season standing became ‘fixed’ much earlier in the season than was the case with the randomized leagues. In the Premier League, 76.9% of the variance in the final standings was explained by round-10, 87.0% by round-20, and 93.9% by round-30. Reordering of match fixtures appeared to alter the shape of the tau-distance curves. Conclusions All soccer leagues appear to conform to mathematical laws, which constrain the league standings as the season progresses. This means that partial standings can be used to predict end-of-season league position with reasonable accuracy.

The aim of this study was to investigate the prevalence of oral contraceptive use in domestic rugby union, to compare symptomology by contraceptive use, and to determine symptom management strategies. Additionally, to characterise the perceived influence of oral contraceptive use and non-use on wellness and performance. A total of 238 Premiership and Championship women’s rugby union players completed an online questionnaire. The survey was comprised of questions relating to player characteristics, hormonal or non-hormonal contraceptive characteristics, perceived symptomology, symptom management strategies, and performance and wellness characteristics. The prevalence of oral contraceptive users was 26%. Non-hormonal contraceptive users reported greater perceived negative symptomology (i.e., back pain, nausea, sore breasts) and performance and wellness effects (i.e., fatigue, stress, mood, concentration, power, match-play) than oral contraceptive users. The most common symptom management strategies were medication (33%), nutritional interventions (20%), and training modulation (20%). Twelve percent of players had previously spoken to staff about their menstrual cycle (i.e., regular and irregular) or contraceptive use. The most common barriers to speaking to staff were ‘male staff’ (29%) and ‘club culture’ (24%). The importance of assisting non-hormonal contraceptive users in managing symptoms is evident. Emphasis on overcoming barriers to staff-player dialogue regarding menstrual/contraceptive cycle is required.

The aim of this study was to investigate the prevalence of oral contraceptive use in domestic rugby union, to compare symptomology by contraceptive use, and to determine symptom management strategies. Additionally, to characterise the perceived influence of oral contraceptive use and non-use on wellness and performance. A total of 238 Premiership and Championship women’s rugby union players completed an online questionnaire. The survey was comprised of questions relating to player characteristics, hormonal or non-hormonal contraceptive characteristics, perceived symptomology, symptom management strategies, and performance and wellness characteristics. The prevalence of oral contraceptive users was 26%. Non-hormonal contraceptive users reported greater perceived negative symptomology (i.e., back pain, nausea, sore breasts) and performance and wellness effects (i.e., fatigue, stress, mood, concentration, power, match-play) than oral contraceptive users. The most common symptom management strategies were medication (33%), nutritional interventions (20%), and training modulation (20%). Twelve percent of players had previously spoken to staff about their menstrual cycle (i.e., regular and irregular) or contraceptive use. The most common barriers to speaking to staff were ‘male staff’ (29%) and ‘club culture’ (24%). The importance of assisting non-hormonal contraceptive users in managing symptoms is evident. Emphasis on overcoming barriers to staff-player dialogue regarding menstrual/contraceptive cycle is required.

Important decisions surrounding talent identification (TID), talent development (TD) and (de)selection within elite youth soccer are often grounded in the subjective opinions of coaches. These opinions often stem from coaches’ observations of player performance, which have been shown to be susceptible to several biases. Additionally, previous research has failed to establish specific criteria on which such opinions are based, aside from a coach's own intuition and practical experience. This study aimed to create a communal language and aligned criteria for the specific purpose of evaluating players’ performances. Semi-structured interviews were undertaken with nine experienced coaches (13.6 ± 10.8 years) from a professional UK soccer academy to identify coaches’ perceptions of key position-specific soccer actions, performed during differing moments of the game, for evaluating individual match performance. Thematic analysis of the interview data permitted the extraction of several themes, posited to encompass the position-specific soccer actions highlighted by the coaches. Themes for outfield positions included attacking skills; defending skills; movements to receive, create or exploit space; receiving and releasing skills; support play; end product; press, recover to the ball, man or space; and tactical understanding. Goalkeeper themes included tactical understanding, positioning relative to the ball, danger, teammates and opponents, play forward, support play, choice of action and range of distribution. This study highlights an applied approach of creating a shared mental model for appraising player performances, which can facilitate discussion and knowledge exchange between coaches and practitioners, with the intention of improving decision-making around TID, TD and (de)selection decisions.

Leg strength and multidirectional speed qualities have repeatedly been linked with increased performance during Rugby League (RL) match play and associated with career attainment. However, very little of this evidence for strength has been gained through unliteral measurements with no study available that has examined the impact of strength asymmetry, in this population, on speed qualities in RL players. Therefore, this study examined the association between unilateral strength and as a novel development the subject with the most extreme asymmetry was identified for further analysis. 50 RL players undertook the rear foot elevated split squat five repetition maximum, 20 m linear sprint and modified 505 change of direction test. The mean leg strength for the group was 88.92 ±12.59 kg, when divided by body weight the mean relative strength (REL) was 1.03 ±0.17 kg/kg and the mean asymmetry was 3.21 ±5.70 %. The participant with the greatest asymmetry (subject A) had an imbalance of 33% and a mean leg strength of 75 kg (REL = 0.78 kg/kg) and a body mass one standard deviation above the group mean. Analysis of the group’s data and that of subject A did not indicate that leg strength asymmetry was either frequent or harmful, with respect to speed performance. However, relative leg strength was associated with both improved linear and multidirectional speed. Practitioners are recommended to prioritise the development of relative leg strength and disregard the aspiration for between leg performance symmetry.

The purpose of this study was to evaluate the anthropometric and performance characteristics of high-level youth female soccer players by annual-age category (Under 10 (U10)–U16). Data were collected from 157 female soccer players (U16, n = 46; U14, n = 43; U12, n = 38; U10, n = 30), recruited from three high-level female soccer academies in England. Players completed assessments of anthropometry (height and body mass), isometric mid-thigh pull strength, jump height, aerobic capacity, change of direction (505-left/right) and speed (10 and 30 m). Magnitude based-inferences were used to assess for practical significance between consecutive age groups. Height (very likely–most likely), body mass (very likely–most likely), absolute strength (most likely), jump height (likely–very likely) and distance on the YYIRL1 (possibly–most likely) were greater in older players. Both speed and change of direction time were most likely to very likely lower in older players. However, only most likely trivial–possibly trivial differences were observed in relative strength between age groups. Findings suggest that physical characteristics except for relative strength differentiate by age categories. These findings provide comparative data and target reference data for such populations and can be used by coaches and practitioners for player development purposes. Practitioners should be aware that relative strength does not differ between age categories in high-level youth female soccer players.

Purpose: Despite the known health and wellbeing benefits of taking part in sport for children and adolescents, it is reported that sports participation declines during adolescence. The purpose of this study was to explore current organized youth sport participation rates across Europe for both males and females and update current understanding. Method: Sport participation registration data was collected for 18 sports from 27 countries. In total, participation data was collected from over 5 million young people from Under 8s (U8s) to Under 18s (U18s). Differences in the participation rates between age categories were investigated using a generalized linear mixed effects model. Results: Overall, males were four times more likely to participate in organised youth sport than females’ participants, with this trend apparent across all age categories and across most sports. There was a significant decrease across sports in participation rates for males during adolescence from U14-U16 and U16-U18. There was a significant decrease in participation rates for females from U14-U16 for most sports except but an increase in participation rates from U16-U18 for 12 out of 18 sports. Soccer (1262%), wrestling (391%) and boxing (209%) were the sports that had greater male sport participation rates. In contrast, dance sports (86%) and volleyball (63%) had more female participants than males. This research shows male sports participation is significantly greater than female in youth sport across Europe. Conclusion: Furthermore, findings showed that for both male and female participants, participation rates increased from U8-U14 for the majority of sports followed by reduced participation rates during adolescence. Findings of this research can be used by national governing bodies and sporting organizations to inform youth sport participation initiatives.

Background An increasing number of epidemiological studies assessing the incidence, prevalence and severity of injury in youth female sport are available. However, no study has sought to synthesise the current evidence base across all youth female sports. As such, a systematic review and meta-analysis of injury in this cohort is necessary to understand the diversity of injury and its associated burden between sports in addition to identifying the density of research available. Objective To conduct a systematic review and meta-analysis of epidemiological data of injuries in youth female athletes with particular attention to injury incidence, mean days lost and injury burden. Methods Searches were performed in PubMed, EBSCO (SportDiscus with Full Text MEDLINE, APA PsycInfo, CINAHL, Academic Search Complete) and Cochrane databases. Studies were considered if they reported time-loss injury incidence or prevalence in youth female (≤ 19 years old) athletes. Study quality and risk of bias was assessed using SIIS STROBE extension, Newcastle Ottawa Scale, and funnel plots, respectively. Injury incidence and burden rate data were modelled using a mixed-effect Poisson regression model. Days lost data were modelled using a generalised linear mixed model. Results Thirty-two studies were included. The overall incidence rate, mean days lost per injury, and burden rate was 4.4 injuries per 1000 h (95% CI 3.3–5.9), 10 days (95% CI 6–15), and 46 days per 1000 h (95% CI 23–92), respectively. Forty percent of athletes sustained at least one time-loss injury. Competitive level was a significant moderator for match and training injury incidence, with elite youth athletes presenting greater pooled injury incidence estimates than non-elite athletes (p = 0.0315 and p = 0.0047, respectively). The influence of moderators on days lost and injury burden could not be conducted due to an insufficient number of studies for analysis. Conclusion Despite a broad inclusion criterion, there is limited injury surveillance research available across youth female sport. Outside of soccer, little research density is evidenced with single studies available in popular team sports such as Australian Rules Football and Rugby Union. Insufficient study numbers reporting mean days lost and injury burden data were available for analysis, and pooled days lost data could only be estimated for soccer. This highlights a need for future research to report days lost data alongside injury number and exposure so burden can be calculated and the full risk of injury to youth female athletes can be identified.

Understanding the locomotor characteristics of competition can help rugby league (RL) coaches optimise training prescription. To date, no research exists on the locomotor characteristics of women’s RL. The aim was to compare whole match and peak locomotor characteristics of women’s RL competition at international (RL World Cup [WRLWC]) and domestic level (Super League [WSL]). Microtechnology data were collected from 58 players from 3-WSL clubs and 1-WRLWC team. Participants were classified into forwards (n = 30) and backs (n = 28). Partial least squares correlation analysis established which variables were important to discriminate between the level of competition (international vs. domestic) and positional group (forwards vs. backs). Linear mixed-effects models estimated the differences between standards of competition and positional group for those variables. International forwards were most likely exposed to greater peak 1-min average acceleration (standardised mean difference = 1.23 [0.42 to 2.04]) and peak 3-min average acceleration (1.13 [0.41 to 1.85]) than domestic forwards. International backs likely completed greater peak 1-min average acceleration (0.83 [0.08 to 1.58]) than domestic backs and possibly greater high-speed-distances (0.45 [−0.17 to 1.07]). Findings highlight the need for positional specific training across levels to prepare representative players for the increased match characteristics of international competition.

The purpose of this study was to determine the importance of physical qualities for speed and change of direction (CoD) ability in female soccer players. Data were collected on 10 female soccer players who were part of a professional English Women’s Super League team. Player assessments included anthropometric (stature and body mass), body composition (dual-energy X-ray absorptiometry), speed (10m, 30m sprint), CoD ability (505 agility), aerobic (Yo-Yo Intermittent Recovery Test), lower-body strength (bilateral knee extensions) and power (countermovement jump [CMJ], squat jump [SJ], 30cm drop jump [DJ]) measures). The relationships between the variables were evaluated using eigenvector analysis and Pearson correlation analysis. Multiple linear regression revealed that the performance variables (10 and 20m speed, mean 505, and CoD deficit mean) can be predicted with almost 100% accuracy (i.e. adjusted R2 > 0.999) using various combinations of the predictor variables (DJ height, CMJ height, SJ height, lean body mass). An increase of one standard deviation (SD) in DJ height was associated with reductions of -5.636 and 9.082 SD in 10 m and 20 m sprint times. A one SD increase in CMJ also results in a reduction of -3.317 and -0.922 SD respectively in mean 505 and CoD deficit mean values. This study provides comparative data for professional English female soccer players that can be used by strength and conditioning coaches when monitoring player development and assessing the effectiveness of training programmes. Findings highlight the importance of developing reactive strength to improve speed and CoD ability in female soccer players.

Women’s rugby (rugby league, rugby union and rugby sevens) has recently grown in participation and professionalisation. There is under-representation of women-only cohorts within applied sport science and medicine research and within the women’s rugby evidence base. The aims of this article are: Part 1: to undertake a systematic-scoping review of the applied sport science and medicine of women’s rugby, and Part 2: to develop a consensus statement on future research priorities. This article will be designed in two parts: Part 1: a systematic-scoping review, and Part 2: a three-round Delphi consensus method. For Part 1, systematic searches of three electronic databases (PubMed (MEDLINE), Scopus, SPORTDiscus (EBSCOhost)) will be performed from the earliest record. These databases will be searched to identify any sport science and medicine themed studies within women’s rugby. The Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews will be adhered to. Part 2 involves a three-round Delphi consensus method to identify future research priorities. Identified experts in women’s rugby will be provided with overall findings from Part 1 to inform decision-making. Participants will then be asked to provide a list of research priority areas. Over the three rounds, priority areas achieving consensus (≥70% agreement) will be identified. This study has received institutional ethical approval. When complete, the manuscript will be submitted for publication in a peer-reviewed journal. The findings of this article will have relevance for a wide range of stakeholders in women’s rugby, including policymakers and governing bodies.

Female sports have recently seen a dramatic rise in participation and professionalism world-wide. Despite progress, the infrastructure and general sport science provisions in many female sports are behind their male counterparts. From a performance perspective, marked differences in physical and physiological characteristics can be seen between the sexes. Although physical preparation practices for male athletes are known, there are currently no published literature pertaining exclusively to female athletes. This information would provide invaluable data for both the researcher and practitioner alike. This survey therefore aimed to examine current practices utilized in female rugby codes (union, league, and sevens). A questionnaire assessing seasonal physical preparation practices, recovery, monitoring and sport science technology, and unique aspects in female rugby was developed. Thirty-seven physical preparation practitioners (32 males, 5 females) responded to the questionnaire. Most participants (78%) worked with national or regional/state level female athletes. Performance testing was more frequently assessed in the pre- (97%) and in-season (86%), than off-season (23%). Resistance, cardiovascular, sprint and plyometric training, and recovery sessions were all believed to be important to enhancing performance and implemented by most participants (≥ 89%). Sport science technologies were commonly (54%) utilized to inform current practice. Menstrual cycle phase was monitored by 22% of practitioners. The most frequently reported unique considerations in female rugby codes included psycho-social aspects (41%), the menstrual cycle (22%), and physical differences (22%). Practitioners working with female rugby can use the presented data to inform and develop current practices.

Objectives: In part 1, the objective was to undertake a systematic scoping review of applied sports science and sports medicine in women’s rugby, and in part 2 to develop a consensus statement on future research priorities. Design: In part 1, a systematic search of PubMed (MEDLINE), Scopus and SPORTDiscus (EBSCOhost) was undertaken from the earliest records to January 2021. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020, the PRISMA extension for Scoping Reviews, and the PRISMA extension protocols were followed. In part 2, 31 international experts in women’s rugby (ie, elite players, sports scientists, medical clinicians, sports administrators) participated in a three-round Delphi consensus method. These experts reviewed the findings from part 1 and subsequently provided a list of priority research topics in women’s rugby. Research topics were grouped into expert-based themes and expert-based subthemes via content analysis. Expert-based themes and expert-based subthemes were ranked from very low to very high research priority on a 1–5 Likert scale. Consensus was defined by ≥70% agreement. The median research priority agreement and IQR were calculated for each expert-based theme and subtheme. Data sources: PubMed (MEDLINE), Scopus and SPORTDiscus (EBSCOhost). Eligibility criteria for selecting studies: Studies were eligible for inclusion if they investigated applied sports science or sports medicine in women’s rugby. Results: In part 1, the systematic scoping review identified 123 studies, which were categorised into six sports science and sports medicine evidence-based themes: injury (n=48), physical performance (n=32), match characteristics (n=26), fatigue and recovery (n=6), nutrition (n=6), and psychology (n=5). In part 2, the Delphi method resulted in three expert-based themes achieving consensus on future research priority in women’s rugby: injury (5.0 (1.0)), female health (4.0 (1.0)) and physical performance (4.0 (1.0)). Summary/Conclusion: This two-part systematic scoping review and Delphi consensus is the first study to summarise the applied sports science and sports medicine evidence base in women’s rugby and establish future research priorities. The summary tables from part 1 provide valuable reference information for researchers and practitioners. The three expert-based themes that achieved consensus in part 2 (injury, female health and physical performance) provide clear direction and guidance on future research priorities in women’s rugby. The findings of this two-part study facilitate efficient and coordinated use of scientific resources towards high-priority research themes relevant to a wide range of stakeholders in women’s rugby.

This study investigated the seasonal change in physical performance of 113 (Under 10: U10 (n=20), U12 (n=30), U14 (n=31) and U16 (n=32)) elite youth female soccer players. Players completed testing pre-, mid- and post-season, including speed (10 and 30m sprint), change of direction (CoD; 505 test), power (Countermovement jump, CMJ), strength (isometric midthigh pull) and aerobic capacity (YoYo Intermittent Recovery Test Level 1; YYIRL1).

The purpose of this study was to evaluate the annual and long-term (i.e., 4 years) development of anthropometric and physical characteristics in academy (16-20 years) rugby league players. Players were assessed at the start of preseason over a 6-year period and were required to be assessed on consecutive years to be included in the study (Under 16-17, n = 35; Under 17-18, n = 44; Under 18-19, n = 35; Under 19-20, n = 16). A subset of 15 players were assessed for long-term changes over 4 years (Under 16-19). Anthropometric (height, body mass, sum of 4 skinfolds) and physical (10- and 20-m sprint, 10-m momentum, vertical jump, yo-yo intermittent recovery test level 1, 1 repetition maximum [1RM] squat, bench press, and prone row) assessments were collected. Paired t-tests and repeated measures analysis of variance demonstrated significant annual (e.g., body mass, U16 = 76.4 ± 8.4, U17 = 81.3 ± 8.3 kg; p < 0.001, d = 0.59) and long-term (e.g., vertical jump, Under 16 = 44.1 ± 3.8, Under 19 = 52.1 ± 5.3 cm; p < 0.001, d = 1.74) changes in anthropometric and physical characteristics. Greater percentage changes were identified between the Under 16-17 age categories compared with the other ages (e.g., 1RM squat, U16-17 = 22.5 ± 19.5 vs. U18-19 = 4.8 ± 6.4%). Findings demonstrate the annual and long-term development of anthropometric and physical characteristics in academy rugby league players establishing greater changes occur at younger ages upon the commencement of a structured training program within an academy. Coaches should understand the long-term development of physical characteristics and use longitudinal methods for monitoring and evaluating player performance and development.

In 2016, ICCE and Leeds Beckett University, together with another six European organisations develop project ICOACHKIDS thanks to an Erasmus+ Sport grant. The project aimed to create high quality, free resources for youth sport coaches to support the creation of a suitably trained coaching workforce. The project delivered the ICOACHKIDS Coaching Children Literature Review, the ICOACHKIDS Pledge, the European Coaching Children Curriculum, the ICOACHKIDS website and three Massive Open Online Courses. The success of the project was unprecedented attracting attention and interest from non-EU nations, International Sports Federations and Global players in health and industry. Championing a ‘kids first’ and ‘coaching matters’ ethos, ICOACHKIDS continues to harness global interest and momentum for the development of a global sport system that provides a safe and supportive environment for children everywhere. This session will review the achievements of ICOACHKIDS to date as well as the latest developments, including the creation of the Global Movement Committee, the development of a new interactive website, the production of the ICOACHKIDS Essential videos in conjunction with Nike, and the implementation of the new Erasmus+ project ICOACHKIDS+ conducting research to create strategies to minimize sport dropout as well as fostering the development of holistic talent development environments.

Two of the leading competitions in rugby league are the European Super League (SL) and Australasian National Rugby League (NRL); however, they adopt different officiating systems. The SL operates with one referee, whereas the NRL operates with two referees (NRL head and NRL pocket referees). There is currently no research comparing the movement demands of the referees using these two systems. This study evaluated the movement demands of SL referees and NRL head and pocket referees during rugby league match play using global positioning system (GPS) tracking. With institutional ethical approval, time–motion analysis was undertaken on 8 full-time SL referees and 19 NRL referees using portable 10 Hz GPS devices (MinimaxX; Catapult Sports, Australia) during the SL and NRL 2013 seasons. A total of 230 matches (SL, n = 144; NRL head, n = 41; NRL pocket, n = 45) were analysed using Sprint software (Catapult Innovations, Australia). A one-way ANOVA was conducted with a Bonferroni post hoc to assess the differences between referees in addition to Cohen’s d effect sizes. The SL referees (6900 ± 830 m) and NRL head referees (7253 ± 1164 m) covered similar distances during match play, whilst the NRL pocket referees covered significantly greater distance (7539 ± 930 m, P < 0.001, d = 0.73) than the SL referees. When movement was categorised into velocity classifications (Rampini et al., 2007, International Journal of Sports Medicine, 28, 228–235) SL referees performed a significantly greater number of high-intensity efforts (9.7 ± 7.4) between 5.51 and 7.00 m · s-1 compared to both the NRL head (6.5 ± 4.2; P = 0.015, d = 0.51) and NRL pocket referees (6.4 ± 4.2; P = 0.009, d = 0.56). SL referees produced a similar number of low-intensity efforts (2.01–4.00 m · s-1) to the NRL head (215.0 ± 34.0 vs. 223.2 ± 45.9) and pocket referees (228.4 ± 37.9). The SL referees covered significantly less distance (3310 ± 510 m) accelerating between 0.00 and 1.00 m · s-2 than the NRL head (3609 ± 692 m; P = 0.010, d = 0.49) and the NRL pocket referees (3770 ± 631 m; P < 0.001, d = 0.80). There was no difference between SL (248 ± 186 m), NRL head (253 ± 176 m) and NRL pocket (268 ± 180 m) referees for distance covered when accelerating at >1.00 m · s-2. A comparison of the one-referee (SL) system with the two-referee (NRL head) system shows no effect on the total distance covered, low-intensity efforts or distance covered when accelerating above 1.00 m · s-2, during match play. However, the SL referees are required to perform more high-intensity efforts and cover less distance accelerating between 0.00 and 1.00 m · s-2 than NRL referees. This preliminary data suggest that the different refereeing systems may influence the movement demands of the referees.

Professional rugby league clubs implement training programmes for the development of anthropometric and physical characteristics within an academy programme. However, research that examines seasonal changes in these characteristics is limited. The purpose of the study was to evaluate the seasonal changes in anthropometric and physical characteristics of academy rugby league players by age category (i.e., under 14, 16, 18, 20). Data were collected on 75 players pre- and postseason over a 6-year period (resulting in a total of 195 assessments). Anthropometric (body mass, sum of 4 skinfolds) and physical (10- and 20-m sprint, vertical jump, Yo-Yo intermittent recovery test and 1 repetition maximum squat, bench press, and prone row) measures were collected. The under 14s and 16s showed greater seasonal improvements in body mass (e.g., under 14s = 7.4 ± 4.3% vs. under 20s = 1.2 ± 3.3%) and vertical jump performance than under 18s and under 20s. In contrast, under 18s and under 20s players showed greater seasonal improvements in Yo-Yo performance and 10-m sprint (e.g., under 14s = 1.3 ± 3.9% vs. under 20s = -1.9 ± 1.2%) in comparison to under 14s and under 16s. Seasonal strength improvements were greater for the under 18s compared with under 20s. This study provides comparative data for seasonal changes in anthropometric and physical characteristics within rugby league players aged 13-20 years. Coaches should be aware that seasonal improvements in speed may not exist within younger age categories, until changes in body mass stabilize and consider monitoring changes in other characteristics (e.g., momentum). Large interplayer variability suggests that player development should be considered on an individual and longitudinal basis.

The purpose of the present study was to evaluate the anthropometric and physical characteristics of English academy rugby league players by annual-age category (under 16s-under 20s) and between backs and forwards. Data were collected on 133 academy players over a 6-year period (resulting in a total of 257 assessments). Player assessments comprised of anthropometric (height, body mass, sum of 4 skinfolds) and physical (vertical jump, 10- and 20-m sprint, estimated V[Combining Dot Above]O2max via the yo-yo intermittent recovery test level 1, absolute 1 repetition maximum [1RM], and relative squat, bench press, and prone row) measures. Univariate analysis of variance demonstrated significant (p ≤ 0.05) increases in height, body mass, vertical jump, absolute, and relative strength measures across the 5 annual-age categories (e.g., body mass: under 16s = 75.2 ± 11.1, under 20s = 88.9 ± 8.5 kg; vertical jump: under 16s = 45.7 ± 5.2, under 20s = 52.8 ± 5.4 cm; 1RM bench press: under 16s = 73.9 ± 13.2, under 20s = 114.3 ± 15.3 kg). Independent t-tests identified significant (p ≤ 0.05) differences between backs and forwards for anthropometric (e.g., under 16s body mass: backs = 68.4 ± 8.6, forwards = 80.9 ± 9.7 kg) and physical (e.g., under 19s 20-m sprint: backs = 3.04 ± 0.08, forwards = 3.14 ± 0.12s; under 18s relative squat: backs = 1.65 ± 0.18, forwards = 1.51 ± 0.17 kg·kg) characteristics that were dependent on the age category and measure assessed. Findings highlight that anthropometric and physical characteristics develop across annual-age categories and between backs and forwards in academy rugby league players. These findings provide comparative data for such populations and support the need to monitor player development in junior rugby league players.

Purpose: Longitudinal studies assessing the seasonal development of strength, speed and power qualities are limited in youth soccer players. The purpose of this study was to evaluate the seasonal changes in the physical development of elite youth soccer players across Pre-, Circa- and Post-Peak Height Velocity (PHV), against a similar age and maturity matched control groups. Methods: One-hundred and twelve male elite youth soccer players (Pre-PHV n = 55; Circa-PHV n = 21; Post-PHV n = 36) and 38 controls consisting of non-elite active participants (Pre-PHV n = 18; Circa-PHV n = 10; Post-PHV n = 10) all undertook isometric mid-thigh pull strength, 10–30 m sprints, change of direction speed (CODs) and countermovement jump (CMJ) tests pre- and post-season. Results: The elite Circa-PHV improved greater than the control group for all physical qualities between pre- and post-season. The elite Pre-PHV improved greater in sprints, CODs, CMJ jump height and strength while the elite Post-PHV group improved more in CODs and strength than their respective control groups. Conclusion: Findings suggest that systematic academy soccer training enhances the development of physical qualities in youth soccer players but maturity status may impact upon such adaptations.

Purpose: To evaluate the movement and physiological demands of the Australasian National Rugby League (NRL) referees, officiating with a ‘two referee’ (i.e., ‘lead’ and ‘pocket’) system and to compare the demands of the lead referee and pocket referees. Methods: 10 Hz global positioning system devices were used to obtain 86 data sets (‘lead’, n=41; ‘pocket’, n=45) on 19 NRL referees. Total distance, relative distance covered and heart rate per half and across match-play was examined within and between referees using t-tests. Distance, time and number of movement 'efforts' were examined in six velocity classifications (i.e., standing <0.5; walking 0.51–2.0; jogging 2.01-4.0; running 4.01-5.5; high speed running 5.51-7.0; sprinting > 7.0 m.s-1) using ANOVA. Cohen's d effect sizes were reported. Results: There were no significant differences between the ‘lead’ and ‘pocket’ referee for any movement or physiological variable. There was an overall significant (large; very large) effect for distance (% distance) and time (% time) (P < 0.001) between each velocity classification for both the ‘lead’ and ‘pocket’ referee. Both roles covered the largest distance and number of efforts at velocities between 0.51–2.0 m.s-1 and 2.01-72 4.0 m.s-1, which were interspersed with efforts >5.51 m.s-1. Conclusions: Findings highlight the intermittent nature of rugby league refereeing, but show that there were no differences in the movement and physiological demands of the two refereeing roles. Findings are valuable for those responsible for the preparation, training and conditioning of NRL referees, and to ensure training prepares for and simulates match demands.

Rugby league referees have the responsibility of enforcing the laws of the game and can influence the outcome based on their decisions. Performance demands inherent in refereeing involve fitness and positioning, law knowledge and application, contextual judgement and game management (Weston et al., 2012, International Journal of Sports Medicine, 42, 615–617). No study to date has investigated the relationship between the physiological and movement demands of refereeing and penalty accuracy. To quantify penalty accuracy scores of rugby league referees and determine the relationship with total distance covered (TD), high intensity distance (HIT) and mean heart rate per half and 10-min period of a match. With institutional ethical approval, all 8 professional Super League referees participated in this study. During the 2012 season, 148 Super League matches were analysed using 10Hz GPS units (MinimaxV4; Catapult Sports, Australia) and 1-Hz heart rate monitors (Polar Electro, Kempele, Finland). Decision-making demands were quantified using Opta Stats (Leeds, UK), which were retrospectively reviewed by an expert referee review panel to determine the accuracy of decisions when awarding or not awarding a penalty. A dependant t-test was used to assess the differences between halves. Repeated measures ANOVA was conducted with a Bonferroni post hoc to assess the differences between 10-min match periods, in addition to Cohen’s d effect sizes. Pearson’s product correlation was used to determine relationships. Super League referees made the correct penalty decision on 74 ± 5% of occasions. Significantly more distance was covered (3586 ± 394 vs. 3514 ± 424 m, P = 0.009, d = 0.18), and a significantly greater heart rate (154 ± 9 vs. 149 ± 9 beats.min-1, P = 0.001, d = 0.56) was achieved in the first compared to the second half. There was no significant difference (P = 0.812) in penalty accuracy (75 ± 4 vs. 73 ± 6 %) or HIT (P = 0.081) between halves. When observed per half and 10 minute periods, there was no significant relationship between penalty accuracy scores and TD (r = –0.023, P = 0.645), HIT (r = 0.093, P = 0.18) or heart rate (r = 0.129, P = 0.135). Findings suggest that the physiological and movement demands of refereeing in rugby league are not significantly related to penalty accuracy scores per 40-min or 10-min period. While it has been observed that there was no significant relationship between TD, HIT or heart rate and accuracy, further research is required to investigate confounding variables (i.e. refereeing experience and fitness levels) that may further influence penalty accuracy. Given the small sample population of professional referees (n = 8), a case study approach to future research is recommended.

Till, K, Jones, B, Darrall-Jones, J, Emmonds, S, and Cooke, C. Longitudinal development of anthropometric and physical characteristics within academy rugby league players. J Strength Cond Res 29(6): 1713-1722, 2015-The purpose of this study was to evaluate the annual and long-term (i.e., 4 years) development of anthropometric and physical characteristics in academy (16-20 years) rugby league players. Players were assessed at the start of preseason over a 6-year period and were required to be assessed on consecutive years to be included in the study (Under 16-17, n 35; Under 17-18, n=44; Under 18-19, n=35; Under 19-20, n=16). A subset of 15 players were assessed for long-term changes over 4 years (Under 16-19). Anthropometric (height, body mass, sum of 4 skinfolds) and physical (10-and 20-m sprint, 10-m momentum, vertical jump, yo-yo intermittent recovery test level 1, 1 repetition maximum [1RM] squat, bench press, and prone row) assessments were collected. Paired t-tests and repeated measures analysis of variance demonstrated significant annual (e.g., body mass, U16=76.4 ± 8.4, U17=81.3 ± 8.3 kg; p < 0.001, d=0.59) and long-term (e.g., vertical jump, Under 16=44.1 ± 3.8, Under 19=52.1 ± 5.3 cm; p < 0.001, d=1.74) changes in anthropometric and physical characteristics. Greater percentage changes were identified between the Under 16-17 age categories compared with the other ages (e.g., 1RM squat, U16-17 22.5 ± 19.5 vs. U18-19 4.8 ± 6.4%). Findings demonstrate the annual and long-term development of anthropometric and physical characteristics in academy rugby league players establishing greater changes occur at younger ages upon the commencement of a structured training program within an academy. Coaches should understand the long-term development of physical characteristics and use longitudinal methods for monitoring and evaluating player performance and development.

Given the importance of the environment in athlete development, recent years have seen an increase in research examining Talent Development Environments (TDEs). However, most research is limited to a single nation and the athletes’ perspective with little consideration of the views of parents or coaches. This study addresses these limitations by examining adolescent (13–18 years) athletes’ (n=202), parents’ (n=178) and coaches’ (n=59) perceptions of TDEs from five European nations. Athletes completed the Talent Development Environment Questionnaire-5 (TDEQ-5) (Li et al., 2015), with parents and coaches completing an adapted TDEQ-5. Items and subscales were analysed across athlete, coach, and parent groups. Parents (4.14±1.51) had less-positive perceptions of their associated TDE across all items, compared with athletes (4.42±1.45; p<0.05) and coaches (4.60±1.28; p<0.05). Across groups, Long-term Development (4.79±0.90) was the most positively perceived TDEQ-5 subscale. Support Network (4.02±1.23) and Alignment of Expectations (4.05±1.11) were the least positively perceived TDEQ-5 subscales. Furthermore, Holistic Quality Preparation (4.30±1.07) and Communication (4.47±1.12) scores for athletes and coaches were significantly higher (p<0.001) than parents. As parental perspectives of TDEs are consistently less positive than those of athletes and coaches, future research should explore reasons behind these differences and how they can inform developments considering the broader aims of TDEs. Moreover, recognising the performance and health implications associated with Support Network, Communication and Holistic Quality Preparation, together with the varying perceptions of these across the groups, offers opportunities for further investigation to develop European TDEs.

Despite the increased growth and professionalism of women’s and girls’ soccer in recent years, there is still a paucity of research exploring talent identification and development. It is widely acknowledged that growth and maturation influence the biopsychosocial development of girls and boys differently, which has important implications for talent identification and development in soccer. Therefore, this chapter disentangles gender by providing an overview of existing research in women’s and girls’ soccer as well as offering recommendations for talent identification and development practices. Firstly, the chapter explains how growth and maturation may impact physical development of young female soccer players. Secondly, the chapter considers the psychosocial development of female players. Lastly, the chapter proposes directions for future research and outlines implications for practice.

This study aimed to 1) develop a consensus (≥70% agreement between experts) on injury risk factors specific to women playing rugby league, 2) establish the importance of the identified injury risk factors and the feasibility of mitigating these risk factors and 3) establish context specific barriers to injury risk management. Aim 1: A Delphi panel, consisting of 12 experts in rugby league and injury (e.g., physiotherapists, research scientists) were asked to identify injury risk factors specific to women playing rugby league. Aim 2: seven coaches of women's rugby league teams were asked to rate each risk factor that achieved consensus by their importance and feasibility to manage. Aim 3: Coaches reported barriers which restrict injury risk factor mitigation. Of the 53 injury risk factors which achieved consensus, the five injury risk factors with the highest combination of importance and feasibility ratings were: "poor tackle technique", "a lack of pre-season intensity", "training session are too short", "the current medical standards", and "limited access to physiotherapists". Following the identification of injury risk factors, their feasibility to manage and context specific barriers, this study proposes three constraint driven, integrated solutions which may reduce the barriers which limit injury risk factor management.

Research into the physiological and movement demands of Rugby League (RL) referees is limited, with only one study in the European Super League (SL). To date, no studies have considered decision-making in RL referees. The purpose of this study was to quantify penalty accuracy scores of RL referees and determine the relationship between penalty accuracy and total distance covered (TD), high-intensity running (HIR) and heart rate per 10-min period of match-play. Time motion analysis was undertaken on 8 referees over 148 European SL games during the 2012 season using 10Hz GPS analysis and heart rate monitors. The number and timing of penalties awarded was quantified using Opta Stats. Referees awarded the correct decision on 74 ± 5% of occasions. Lowest accuracy was observed in the last 10-minute period of the game (67 ± 13%), with a moderate drop (ES= 0.86) in accuracy observed between 60-70 minutes and 70-80 minutes. Despite this, there were only small correlations observed between HRmean, total distance, HIR efforts and penalty accuracy. Although a moderate correlation was observed between maximum velocity and accuracy. Despite only small correlations observed, it would be rash to assume that physiological and movement demands of refereeing have no influence on decision-making. More likely, other confounding variables influence referee decision-making accuracy, requiring further investigation. Findings can be used by referees and coaches to inform training protocols, ensuring training is specific to both cognitive and physical match demands.

The purpose of the current study was to investigate the anthropometric, body composition and fitness characteristics of female rugby league players by playing position. Data were collected on 27 players who were part of the English elite women's rugby league squad. Player assessments comprised anthropometric (stature and body mass), body composition (dual-energy X-ray absorptiometry) and fitness (lower-body power [countermovement jump (CMJ), 20 kg jump squat (JS) and 30 cm drop jump], 5, 10, 20, 30, and 40 m sprint, 505 agility, Yo-Yo intermittent recovery test level 1) measures. Players were classified into playing position (i.e., forwards and backs) prior to analysis. A multivariate analysis of variance (MANOVA) demonstrated significant (p<0.05) differences for body mass, stature, total fat, lean mass and percentage body fat between forwards and backs. Positional differences were also observed for speed, agility and lower-body power. Significant relationships were observed between total body fat and all fitness variables, and total lean mass was related to CMJ and JS peak power. This study provides comparative data for female rugby league forwards and backs. Body fat was strongly associated with performance and should therefore be considered in developing fitness characteristics. The relationship to match performance and trainability of these characteristics warrants further investigation.

Due to the focus of research within athletic populations, little is known about the hydration strategies of rugby league referees. We observed all 8 full-time professional referees, during 31 Super League matches to investigate the drinking strategies and magnitude of dehydration (body mass loss) experienced by referees during match play. Referees arrived and remained euhydrated (urine osmolality; pre and post-match 558 ± 310 and 466 ± 283 mOsmol•kg-1). Mean body mass change was -0.7 ± 0.8%, fluid loss was 890 ± 435 g and fluid intake was 444 ± 167, 438 ± 190, 254 ± 108 and 471 ± 221 g during pre-match, first-half, half-time and second-half. This study suggests elite referees adopt appropriate hydration strategies during match-play to prevent large reductions in body mass, although individual variability was observed. Future research should investigate dehydration in referees from other sports and the effects on refereeing performance.

The implementation of long-term athletic development (LTAD) aims to improve health, physical activity and performance of all youth. Contemporary LTAD models suggest that a broad range of physical and psycho-social competencies should be developed in youth, but few resources are available for coaches that describe ‘how’ to achieve these outcomes. This paper overviews a coaching session framework called RAMPAGE (Raise, Activate, Mobilise, Prepare, Activity, Games, Evaluate). The framework provides practitioners with information on what can be planned and delivered and when within a coaching session, across multiple ages and stages of development within multiple contexts (e.g., physical education, talent development).

Talent Development Environments (TDEs) aim to provide the appropriate conditions for youth athletes to realise their full sporting potential. How TDEs are designed and operated is therefore of great importance for the development of elite athletes. Stakeholders are vital in this process, yet their perspectives are poorly understood. This study assessed the quality of TDEs across 5 European countries, comparing athlete, parent and coach perceptions. A total of 571 athletes (Mean age = 15.2 ± 1.5 years), 759 parents and 134 coaches were recruited from TDEs across 27 sports. Participants completed the Talent Development Environment Questionnaire-5 or adapted versions. Overall, perceptions of European TDEs were positive. Coaches reported higher perceptions of TDE quality compared to athletes and parents, athletes reported marginally higher perceptions compared to parents. Across stakeholders, Long-Term Development was highest rated, followed by Communication. Support Network was lowest rated. Stakeholder perceptions varied most for the Holistic Quality Preparation subscale, highlighting perceived differences in TDE support for rounded athlete development. From an organisational perspec- tive, identified strengths and weaknesses provide direction to coach and parent education. Practically, TDE leaders should consider how they can refine stakeholder coordination through integrating stake- holder perceptions as valuable feedback into their environment, especially for intangible factors.

Participation in women’s rugby league has been growing since the foundation of the English women’s rugby league Super League in 2017. However, the evidence base to inform women’s rugby league remains sparse. This study provides the largest quantification of anthropometric and physical qualities of women’s rugby league players to date, identifying differences between positions (forwards & backs) and playing level (Women’s Super League [WSL] vs. International). The height, weight, body composition, lower body strength, jump height, speed and aerobic capacity of 207 players were quantified during the pre-season period. Linear mixed models and effects sizes were used to determine differences between positions and levels. Forwards were significantly (p < 0.05) heavier (forwards: 82.5 ± 14.8kg; backs: 67.7 ± 9.2kg) and have a greater body fat % (forwards: 37.7 ± 6.9%; backs: 30.4 ± 6.3%) than backs. Backs had significantly greater lower body power measured via jump height (forwards: 23.5 ± 4.4cm; backs: 27.6 ± 4.9cm), speed over 10m (forwards: 2.12 ± 0.14s; backs: 1.98 ± 0.11s), 20m (forwards: 3.71 ± 0.27s; backs: 3.46 ± 0.20s), 30m (forwards: 5.29 ± 0.41s; backs: 4.90 ± 0.33s), 40m (forwards: 6.91 ± 0.61s; backs: 6.33 ± 0.46s) and aerobic capacity (forwards: 453.4 ± 258.8m; backs: 665.0 ± 298.2m) than forwards. Additionally, international players were found to have greater anthropometric and physical qualities in comparison to their WSL counterparts. This study adds to the limited evidence base surrounding the anthropometric and physical qualities of elite women’s rugby league players. Comparative values for anthropometric and physical qualities are provided which practitioners may use to evaluate the strengths and weaknesses of players, informing training programs to prepare players for the demands of women’s rugby league.