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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 3 × 60 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 is gathered. [ABSTRACT FROM AUTHOR]

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 unilateral 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. Fifty RL players undertook the rear foot elevated split squat 5 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 mass, the mean relative strength (REL) was 1.03 ± 0.17 kg·kg-1, and the mean asymmetry was 3.21 ± 5.70%. The subject with the greatest asymmetry (subject A) had an imbalance of 33% and a mean leg strength of 75 kg (REL = 0.78 kg·kg-1) and a body mass 1 SD 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 prioritize the development of relative leg strength and disregard the aspiration for between leg performance symmetry. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This study compared the influence of match status (drawing, losing, or winning) and possession status (inpossession, 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. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 perspective, identified strengths and weaknesses provide direction to coach and parent education. Practically, TDE leaders should consider how they can refine stakeholder coordination through integrating stakeholder perceptions as valuable feedback into their environment, especially for intangible factors. [ABSTRACT FROM AUTHOR]