International Journal of Sports Science & Coaching

Understanding the factors that influence player retention within elite youth football can be used to enhance current practices. This study investigated an English Category 1 academy to determine if birth quartile, somatic maturity, anthropometric and physical performance characteristics are associated with player retention across the developmental pathway. Birth dates of 355 elite players from Under 11 (U11) to U21 groups were categorised into birth quartiles, and logistic regression (odds ratio) analysis was used to determine the differences in retention. Multilevel modelling compared somatic maturity, anthropometry, countermovement jump, sprint time (10 and 30 m), agility T-test and Yo-Yo Intermittent Recovery Level 1 or 2 performance between retained and dropout players. Logistic regression (odds ratio) analysis revealed no significant differences between birth quartiles for the likelihood of being retained across age groups. Multilevel modelling revealed that retained players were typically older, advanced in maturity and superior in body size and physical performances compared to dropouts, with small to medium effect sizes typically observed. This study indicates that within a highly selective cohort of young football players, somatic maturity, anthropometric and physical performance characteristics, but not birth quartile, distinguish individuals that are subsequently retained or dropout in an age group-dependent manner. Youth football organisations should seek to implement multidisciplinary and dynamic talent selection and retention strategies to prevent inappropriate discrimination and loss of talented young players.

This observational study addresses physical activity levels among youth sport participants as influenced by coaching experience and coaching efficacy. It describes the proportion of moderate-to-vigorous physical activity (MVPA) per sport contextual factor by years of coaching experience and coaching efficacy. Physical activity levels of youth (n = 146) were measured via accelerometer. Contextual factors of practice and physical activity were obtained via direct observation. Coaching experience and efficacy of volunteer coaches (n = 26) were measured by a demographics questionnaire and the coaching efficacy scale. Practices averaged 69.81 min (SD = 13.12) with 39.7% (SE = 1.7) spent in sedentary behavior, 32.2% (SE = 1.5) in MVPA, and 20.6% (SE = 1.2) in vigorous-intensity physical activity (VPA). Spearman-rho coefficients suggest no significant relationship between coaching efficacy and %MVPA (r_s = 0.337, p =0 .092) or %VPA (r_s = 0.200, p = 0.327). Repeated-measures analysis of variance found a significant relationship between direct observation MVPA and practice contextual factors, but not by coaching experience or efficacy. Multiple regression found no significance of either variable in predicting MVPA. Coaching experience and perceived coaching efficacy do not appear to influence MVPA behavior during sport practices; however, it is unclear whether coach education training in this area would. Emphasis on implementing coach training standards to enhance coaches’ confidence to motivate children to be more physically active during practice and opportunities to do so, may improve youth health through physical activity.

Guided by Self-Determination Theory, this study examined the relative importance of perceived coach supports in facilitating at-risk boys’ motivation toward physical activity. Participants were 76 at-risk boys (M_age = 11.87 years, SD = 1.22) at a summer sports camp in the southwestern USA. Data were collected using two established questionnaires and analyzed through commonality analysis. Perceived supports for autonomy, competence, and relatedness together explained 25.5% of variance in autonomous motivation, and perceived competence support was the most powerful predictor. In predicting amotivation (R² = .19, p < .001), perceived competence support and perceived relatedness support were significant individual predictors while perceived autonomy support emerged as a suppressor. Perceived competence support appeared to be the strongest predictor of autonomous motivation, and the three supports were all important to diminishing amotivation. The results suggest that in similar physical activity settings, coaches should provide supports for competency, connectedness, and autonomy among participants.

This study examined track and field coaches’ and parents’ knowledge of (a) the relationship between adolescent and later success, (b) factors contributing to adolescent success, particularly in relation to relative age effects, and (c) optimal athlete development practices, such as the timing of sport specialisation. Fifty-two coaches and 116 parents completed a survey comprising both closed and open questions. Compared to coaches, parents were more likely to believe that successful adults had achieved success during early adolescence and to connect that success to innate ability rather than relative development. However, there was no difference in the proportion of parents and coaches who reported familiarity with the relative age effect (approximately 50%). The most pronounced differences between coaches and players were in relation to optimal youth development practices, with parents more likely to encourage year-round training at an earlier age, and specialising in a single sport at an earlier age. Contrasting the knowledge reported by coaches and parents with the results of quantitative studies of youth development suggests that bespoke education is required for both groups. Furthermore, the explanations provided by parents and coaches for their beliefs about youth sport practices suggest that professional bodies need to provide more nuanced instruction to stakeholders on how to implement general guidelines on healthy youth sport practices into their individual practice.

This study aimed to identify the effects of manipulating the ball type in players’ physical, technical, creative and tactical performance in two small-sided games situations: 4-a-side and 6-a-side. There were four conditions: (i) Football, using regular football ball; (ii) Handball, using handball ball; (iii) Rugby, playing with rugby ball, and (d) Mixed, at every 2 min the ball type was randomly changed. Players’ technical and creative actions were analysed through notational analysis, while GPS positional data were used to process the physical and tactical variables. During the 4-a-side, the rugby and mixed conditions induced more effects. From the physical perspective, there were moderate decreases in the total distance covered (−11.1%; ±3.1% and −6.2; ±3.6) and distance covered while jogging (−11.9%; ±3.6% and −8.0; ±3.9) in both scenarios, respectively. In tactics, there were small to moderate decreases in both conditions in the distance between team’s centroids (−5.5; ±6.0 and −6.8%; ±5.1%) and effective playing space (−16.2; ±9.8 and −20.6; ±12.3), respectively. In turn, all variables were affected by the ball type modification during the 6-a-side compared to the Football balls. Modifying the type of ball promoted small to moderate decreases in the number of successful passes and dribbles, in the fluency and versatility, as well as in most of the physical variables. Additionally, changing the ball type has also affected (small decreases) in the regularity in the distance between teams. Coaches may promote variability in the training tasks using different balls to develop the players’ adaptive movement behaviours.

To evaluate collective (macro) performance data in the Chinese Super League, social network analyses and graph theory were implemented in team sports performance analyses. For each team, we constructed a weighted and directed network in which nodes corresponded to players and arrows to passes. A total of 1200 matches during the 2014–2018 seasons were analysed. The results showed significant differences in general network measures among team competitive levels, match locations and match outcomes. Successful teams and home teams had significantly higher link, diameter, density and cluster coefficient values than did the unsuccessful teams or visiting teams; however, the winning teams had significantly lower density and cluster coefficient 2 values than did the losing teams. This study suggested that successful teams or teams with advantages (home, winner) have a high level of total passes and eigenvalues. This is the first report in which eigenvalues (the degree of a team’s distribution of the ball during the match) were able to capture changes in dynamics between different teams. There were positive correlations between all the network variables and the total shots and no correlations between all the network variables and goals.

Ramadan is characterized by daily abstinence from food and fluid intake from dawn to sunset. The understanding of the Ramadan effects on the diurnal variations of athletic performance is crucial for practitioners, coach and researchers to prepare sport events and optimize performance. The aim of the present study was to reveal the effect of Ramadan on the performance aspect, heart rate and rating of perceived exertion during a karate match. In a randomized counterbalanced, 2 × 2 cross-over order, 22 male and female amateur karate athletes (age = 16.8 years, body mass = 59.1 kg, height = 168.3 cm) participated in simulated karate match at 8–10 a.m. and 5–7 p.m. on three different occasions: 1 week before Ramadan, the second week of Ramadan (during Ramadan), and 2 weeks after Ramadan. Performance aspects were analyzed, and heart rate and rating of perceived exertion were assessed before and immediately after the match at each visit. Our results demonstrated that Ramadan adversely affected time-motion variables (fighting time and preparatory time) and heart rate during simulated karate match (p < 0.05, all). However, heart rate pic response to karate match was higher during Ramadan when compared with before Ramadan and after Ramadan. However, rating of perceived exertion results did not show any variation during Ramadan phases. Concerning the interaction of Ramadan and time of day, fighting time and stoppage time were higher in the evening and in the morning before Ramadan and the inverse during Ramadan, respectively (p < 0.05). In conclusion, Ramadan altered the diurnal variation of performance aspect, in terms of fighting time and stoppage time, during simulated karate match.

This study investigated the return to baseline of movement velocity and maximal strength following a strength-orientated session and power-orientated session in the free-weight back-squat performed with maximal concentric velocity. Fourteen strength-trained males completed a strength-orientated session (five sets of five repetitions @80% of a one-repetition maximum) and a power-orientated session (three sets of six repetitions @50% one-repetition maximum ) in a randomised order over two weeks (e.g. strength week 1, power week 2). The back-squat was then performed with loads of 20%, 40%, 60%, 80%, 90% and 100% one-repetition maximum at 24, 48, 72 and 96 h following the strength and power exercise sessions to assess return to baseline of squat velocity and maximal strength. Dependent variables included one-repetition maximum, back-squat mean velocity and peak velocity and countermovement jump peak velocity. Meaningful changes ((effect size) ≥ −0.60) were reported for mean velocity and peak velocity at loads ≥ 60% one-repetition maximum at 24 and 48 h after the strength-orientated session. Trivial to small (effect size ≤ −0.59) differences were reported for squat velocities following the power-orientated session. Only trivial to small effect size differences were observed for countermovement jump peak velocity and one-repetition maximum at all time points following both sessions. Squat velocity (mean velocity and peak velocity) across the load–velocity profile had recovered at 72 h following the strength-orientated session. However, the return to baseline of squat velocity (mean velocity and peak velocity) did not coincide with the return to baseline of one-repetition maximum or countermovement jump peak velocity. Therefore, measuring and monitoring meaningful changes in velocity may be a more valid and practical alternative in determining full recovery and readiness to train.

The purpose of this study was to determine the intra- and inter-rater reliability of scoring procedures used in the newly developed Basketball Jump Shooting Accuracy Test (BJSAT) and assess for floor and ceiling effects in test performance. Thirty-one semi-professional basketball athletes completed four trials of the BJSAT. The BJSAT contains one jump shot at eight different locations, equally distributed across two- and three-point shots. Intra-rater reliability was determined by assessing the level of agreement between scores live in-person and watching captured video by the same assessor. Inter-rater reliability was determined by examining the level of agreement between two assessors who separately scored the BJSAT while watching captured video. Descriptive statistics and Cohen’s kappa (κ) were calculated to quantify the intra- and inter-rater reliability of the BJSAT. Floor and ceiling effects in scoring outcomes were analyzed to evaluate the suitability of the BJSAT. Significance for the study was set at p <0.05. Intra-rater reliability demonstrated an almost perfect (κ = 0.85, p <0.01) agreement between scores (12.6 ± 2.5 vs. 13.1 ± 2.8). The agreement for inter-rater reliability was rated as substantial (12.3 ± 2.5 vs. 13.5 ± 2.9, κ = 0.70, p <0.01). Floor and ceiling effects were absent in the BJSAT indicating the assessment is suitable for semi-professional basketball athletes. The BJSAT is an assessment where one or multiple assessors can reliably score shooting performance for functions including player monitoring, to assess the efficacy of interventions aimed at improving skills and to assist with team selection across the season.

Talent development in sport is a comprehensive area of research with various conceptualisations of how the body moves and how skills are developed. The sports coaching environment is often criticised for a lack of evidence-based approaches to talent development, driven by limited access to appropriate sources of information. The current conceptualisation of motor learning, which harnesses dynamical systems theory and ecological psychology, is a complex and underdeveloped area in sport. Recommendations for talent development are often lost in complex pedagogies, so there is high demand for practical information on the translation of this knowledge. At its core, ecological dynamics views the body as a complex system which can reorganise to solve challenging problems in different ways, and emphasises that personal experiences, the task and the environment are all interacting. The specific elements of nonlinear development (person), representative learning design (task) and the talent development pathway (environment) are key elements for cricket coaching that are yet to be synthesised for the coaches who provide early learning experiences.

The volleyball spike represents one of the more sophisticated attack actions, and the study of its kinematics has been the aim of several studies. This systematic review summarized and critically appraised the literature on the volleyball spike kinematics. Studies that analysed the 3D kinematics of the volleyball player during spike movements were searched in the PubMed, SCOPUS, Web of Science and SPORTDiscus databases. Eighteen studies met the eligibility criteria and were assessed as high (n = 7), good (n = 6) and limited quality (n = 5). There are strong indications that the spike jump height depends on the velocities of the centre of mass and that the ball speed seems to be related to velocity variables of the spike arm and the trunk of the volleyball player. Cross-court spike performance from position 4 seems to be associated with the trunk rotation of the volleyball player. In addition to the kinematic differences between the sexes, studies analysed the relationship between spike technique performance and injuries. However, further studies are required before a clear relationship can be established. These results may support sports coaches in optimizing athletic performance with adequate technique training and using kinematic cues from the opposing volleyball players to anticipate spike direction.

This systematic review evaluates empirical evidence for intervention studies targeting delivery and improvement of movement competency (MC) within youth athletes. Previous research suggests that youth athletes lack adequate MCs required to meet the demands of training for sport. From the systematic search, studies were included if they involved healthy youth (8–19 years) involved in organised sport (i.e. athletes); used an assessment at two or more time points for assessing MC outcomes; and compared movement quality of a targeted intervention group to a control or comparison group. After removing duplicates, 799 unique articles across six databases were identified and screened, with six studies initially satisfying inclusion criteria. Additional records were identified through searching reference lists (n = 2), with eight articles included. Two authors evaluated and appraised studies for methodological quality using the PEDro assessment; with scores from 4 to 7 points. Five studies reported improvement in ratings of MC in experimental groups, compared to control or comparator groups. The Functional Movement Screen™ was the most common assessment used in five studies. Intensity, length and design of interventions varied, yet all studies revealed inclusion of squats and their derivatives to varying degrees of load from bodyweight to barbells. Future research should explore differences in training session exposures over time, alongside methodological improvements such as participant allocation to minimise baseline differences, blinding of assessors, and where possible athletes to some degree. Charting the course of MC development through multiple time points, along with reporting individual movement task scores, can aid practitioners in dedicating appropriate time to MC development in an athlete’s formative years.

A large body of research has shown that self-regulation is an important aspect underlying athletes’ well-being and performance. However, self-regulation skills are equally important for post-performance situations, particularly with regard to the recovery process. This review highlights relevant self-regulation skills and provides a brief overview of theories, research findings, and practical recommendations regarding self-regulation and recovery in sport and exercise. Recovery self-regulation is defined as the act of identifying one's current state, one's desired future state and undertaking actions to minimize the discrepancy between both states during the recovery phase (e.g., between training sessions or competitions). Several self-regulation skills relevant to this process are discussed in the current review. First, self-monitoring is a central self-regulatory skill for successfully regulating post-performance states. Second, there is an important role for the regulation of cognition and emotion as complete recovery is only accomplished when both physical and mental resources are replenished. Specifically, detachment and mental rest (i.e., ceasing cognitive effort) enable athletes to restore depleted resources. Finally, self-control is often required to initiate appropriate, and sometimes effortful, recovery activities. That is, athletes may have to exert self-control to undertake activities, particularly when they are tired, stressed, or in a negative mood. Developing recovery self-regulation skills will likely benefit athletes’ physical and mental recovery from training and competition, which can have positive effects on long-term health, well-being, and performance.