Mitigating against relative age effects in youth Track & Field: Validating corrective adjustment procedures across multiple events.

OBJECTIVES: With the aim to better identify talented Track & Field performance development, this study estimated the relationships between chronological (decimal) age with 60-m sprint, high jump, triple jump, and pole vault performance. Then, to mitigate against expected Relative Age Effects (RAEs), Corrective Adjustment Procedures (CAPs) were applied to an independent sample. DESIGN: Mixed-longitudinal design examining public data between 2005 and 2019. METHODS: The performances of 5339 Italian sprinters and jumpers (53.1 %) spanning 11.01-17.99 years of age were examined, with trendlines between chronological age and performance established. Related to an independent sample (N = 40,306; female 45.5 %), trendlines were then utilised to apply CAPs and adjust individual performance. Considering raw and adjusted performance data, RAE distributions were examined for the top 25 % and 10 % performers. RESULTS: For all male and female events, quadratic models best summarised the relationships between chronological age and performance (R2 = 0.74-0.89). When examining independent athletes in similar event, RAEs were more pronounced in males (Cramer's V = 0.35-0.14) than females (Cramer's V = 0.29-0.07). For both sexes, RAE magnitude decreased with age and increased according to performance level (i.e., Top25%-Top10%). However, following CAP applications, RAEs were reduced or removed within annual age groups and performance levels. CONCLUSIONS: With RAEs prevalent across Italian youth Track & Field events, findings validate CAPs as a strategy to account for the influence of relative age differences on athletic performance. CAPs help establish a more equitable strategy for performance evaluation and could help improve the efficacy of long-term athlete development programming.

Advancing athlete development: How Percentile Comparison Methods (PCMs) can identify youth developmental profiles.

OBJECTIVES: Inter-individual developmental differences confound the capability to accurately evaluate youth athletic performance, highlighting the need for considerate methodology and analytical approaches. The present study demonstrated how Percentile Comparison Methods (PCMs) were developed, tested, and applied to identify athlete developmental profiles in Australian youth swimming. DESIGN: Cross-sectional. METHODS: Participants were N = 866 female 100-metre (m) Front-Crawl swimmers, aged 9-15 years, competing at 36 Australian regional-national level long course events. At respective events, swim performance time was collated alongside, age, date of birth, and anthropometric measures to identify age group, relative age, and maturity status. Quadratic relative age and maturity status with 100-m performance regression trendlines were generated. Then, individual swim performances at a given relative age or maturity status were converted into percentile rank distributions and compared with raw (unadjusted) annual age-group performance percentile ranks. RESULTS: At a cohort level, initial testing confirmed relative age and maturity-adjusted percentile rankings were associated with general rank improvements for relatively younger and later maturing swimmers compared to raw ranks (and vice versa). When assessing individual swimmer plots, where three percentile rank scores were compared and rank change threshold criteria applied, five Percentile Comparison Method profile types were identified, namely: 'Early Developing' (19 %); 'Later Developing' (18 %); 'Consistent' (15 %); 'Mixed' (38 %) and 'Counteracting' (10 %). Percentile Comparison Method plots helped identify developmentally (dis-)advantaged swimmers; specific factors leading to (dis-)advantage, and likely onward development trajectories. CONCLUSIONS: Overall and with practical considerations, Percentile Comparison Methods can improve the validity of youth athletic performance evaluation as well as inform athlete development programming.

Identifying Differences in Swimming Speed Fluctuation in Age-Group Swimmers by Statistical Parametric Mapping: A Biomechanical Assessment for Performance Development.

The aim of this study was to compare the assessment of swimming speed processed as a discrete variable and as a continuous variable in young swimmers. One-hundred and twenty young swimmers (60 boys: age = 12.91 ± 0.86 years; 60 girls: age = 12.46 ± 0.94 years) were analysed. The dataset for each sex was divided into three tiers: (i) tier #1 - best-performing swimmers; (ii) tier #2: intermediate-performing swimmers, and; (iii) tier #3 - poorest-performing swimmers. As a discrete variable, swimming speed showed significant sex and tier effects, and a significant sex*tier interaction (p < 0.001). Speed fluctuation showed a non-significant sex effect (p > 0.05), a significant tier effect (p < 0.001), and a non-significant sex*tier interaction (p > 0.05). As a continuous variable, the swimming speed time-curve presented significant sex and tier effects (p < 0.001) throughout the stroke cycle, and a significant sex*tier interaction (p < 0.05) in some moments of the stroke cycle. Swimming speed fluctuation analysed as a discrete variable and as a continuous variable can be used in a complementary way. Nonetheless, SPM can provide deeper insight into differences within the stroke cycle. Thus, coaches and practitioners should be aware that different knowledge about the swimmers' stroke cycle can be learned by assessing swimming speed using both methods.

A continuous times-series and discrete measure analysis of two individual divers performing the 3½ pike somersault dive.

Springboard diving training is often focused upon skill repetition to establish movement accuracy, stability and consistency. Within-participant study designs provide the ability to understand how individuals create these skills under different movement strategies. IMUs measured angular velocity time-series data of two athletes performing multiple repetitions of forward 3½ somersault pike dives. Functional Principal Component Analyses (fPCA) were performed to examine individual movement structure and variability. The first five fPC's represented approximately 98% of the variability in angular velocity for both divers. To determine the relative importance of angular velocity variability, Pearson's correlations for pairwise comparisons were used to assess the relationship between fPC scores and discrete performance variables during takeoff, flight and entry. Divers exhibited a different number and types of significant correlations (International = 4; National = 11). Only one correlation was common for both divers; higher angular velocity during Initial Flight and/or Somersault phases resulted in more vertically aligned entry posture (International: fPC1 r = -0.761, p < 0.05; National: fPC3 r = -0.796, p < 0.01). Findings identify individualised angular velocity time-series structure and kinematic performance variables (International = angular; National = linear) that can be used by coaching/sport science teams to optimisation performance success.

The Longitudinal Mediating Influence of Maturation on the Relationship Between Strength and Performance in Male Youth Swimmers.

PURPOSE: To examine the longitudinal relationships between shoulder internal and external rotation (IR and ER) strength, maturity status, and swim performance (aim 1). To determine whether maturity status mediated (partially/fully) the relationship between shoulder IR/ER strength and performance in age-group swimmers (aim 2). METHODS: Using a repeated-measures design, anthropometrics, maturity status, shoulder IR/ER strength, and 200-m front-crawl velocity were assessed over 3 competition seasons in N = 82 Australian male competitive swimmers (10-15 y). For aim 1, linear mixed models examined longitudinal relationships between assessed variables. For aim 2, causal mediation analyses examined proportional (in)direct contributions of maturity status between shoulder IR strength and swim performance. RESULTS: For aim 1, linear mixed models identified a significant relationship between shoulder IR strength and swim performance over time (F1,341.25 = 16.66, P < .001, marginal R2 = .13, conditional R2 = .91). However, maturity status was influential (ΔAkaike information criterion = -75.8, χ2 = 19.98, P < .001), suggesting removal of the shoulder IR strength-swim velocity relationship (F1,214.1 = 0.02, P = .88). For aim 2, mediation analyses identified maturity status as fully mediating the shoulder IR strength-swim velocity relationship (92.30%, P < .001). CONCLUSIONS: Shoulder IR and ER strength did not account for variance in longitudinal age-group swim performance independent of maturity status. Interindividual differences in maturity status fully explained the relationship between shoulder IR/ER strength and swim performance. For practitioners, findings promote the need to account for maturation status and question the rationale for upper-limb strength assessment during maturational years.

Longitudinal changing relationships between growth tempo and vertical stiffness in movement across maturation.

PURPOSE: To determine whether average growth tempo influenced longitudinal relationships between maturity status and coordination capability using a 15-s hopping task (Aim 1). To investigate how differences in absolute growth tempo were associated with change in coordination capability within and across peak growth (Aim 2). METHODS: Participants were N1 = 110 (Aim 1) and N2 = 71 (Aim 2) Australian male competitive swimmers, aged 10-15 years, exposed to repeated-measures tracking (2-years, and 12-months respectively) of maturity status, growth tempo and movement coordination capability. Coordination capability was estimated via vertical stiffness (KV) in a hopping task, reflected by participant mean KV and between-jump coefficient of variation (CV). RESULTS: For Aim 1, log-linear mixed model trends identified maturity status and growth tempo were significantly associated with KV mean and KV CV. For a given maturity status, mean KV was 9% lower in the 'High' average growth tempo group than the 'Low' average tempo group. For Aim 2, mixed repeated-measures analyses of variance identified how time points of increased growth tempo were significantly associated with 7-11% reductions in mean KV, with similar mean KV decrements irrespective of growth tempo group. Meanwhile, KVCV only illustrated progressive longitudinal reductions. CONCLUSIONS: Within maturational progression, short-term accelerations in growth tempo corresponded with short-term decreases in KV mean, suggesting temporary disruptions to movement coordination capability. Measuring growth tempo and applying hopping tasks in specific movement contexts could help consistently identify disturbances in motor coordination.

Maturation-based Corrective Adjustment Procedures (Mat-CAPs) in youth swimming: Evidence for restricted age-group application in females.

Inter-individual differences in maturation-associated development can lead to variations in physical performance, resulting in performance (dis)advantages and maturation selection bias within youth sport systems. To address such bias and account for maturational differences, Maturation-based Corrective Adjustment Procedures (Mat-CAPs) could be beneficial. The present study aimed to: (1) determine maturity timing distributions in youth female swimming; (2) quantify the relationship between maturation status and 100-m front-crawl (FC) performance; (3) implement Mat-CAPs to remove maturational influences upon swimming performance. For Aim 1 and 2, participants were 663 female (10-15 years) swimmers who participated in 100-m FC events at Australian regional, state, and national-level competitions between 2016-2020 and underwent anthropometric assessment (mass, height and sitting height) to estimate maturity timing and offset. For Aim 3, participants aged 10-13 years were categorised into maturity timing categories. Maturity timing distributions for Raw ('All', 'Top 50%' and 'Top 25%') and Correctively Adjusted swim times were examined. Chi-square, Cramer's V and Odds Ratios determined the presence of maturation biases, while Mat-CAPs identified whether such biases were removed in targeted age and selection-groups. Results identified that between 10-13 years, a significantly higher frequency of 'early' maturers was apparent, although tapered toward higher frequencies of 'Late-normative' maturers by 14-15 years. A curvilinear relationship between maturity-offset and swim performance was identified (R2 = 0.51, p<0.001) and utilised for Mat-CAPs. Following Mat-CAPs application, maturity timing biases evident in affected age-groups (10-13 years), and which were magnified at higher selection levels ('Top 50%' & '25%' of swim performances) were predominantly removed. Findings highlight how maturation advantages in females occurred until approximately 13 years old, warranting restricted Mat-CAPs application. Mat-CAPS has the potential to improve female swimmer participation experiences and evaluation.

Video analysis of jockey fall characteristics in horse racing.

OBJECTIVES: To identify characteristics of jockey falls associated with high-risk landings using a modified Equestrian Fall Assessment Instrument. DESIGN: Cross-sectional study. METHODS: Video footage of 22 flat and 58 jump racing falls (N = 80) which occurred in Great Britain, Ireland, and New Zealand from 2013 to 2018 was systematically analysed using the modified Equestrian Fall Assessment Instrument. Race, horse, and jockey-level factors, including the nature of ground contact (landings), were characterised identifying factors associated with high-risk landings. High-risk landings refer to cases where the jockey's head impacted the ground or where there was potential horse impact on the jockey. A multivariable logistic regression model was applied identifying independent variables associated with high-risk landings. RESULTS: In 79 % (63/80) of race falls examined, at least one high-risk landing factor was present. Three independent variables explained 40.3 % of variance in high-risk landings. Lower race class (odds ratio 1.5; 95 % confidence interval 0.96, 2.39; p = 0.054), hanging onto the reins upon ground impact (odds ratio 7.5; 95 % confidence interval 1.04, 53.63; p = 0.028), and no jockey tuck-and-roll behaviour following ground impact (odds ratio 4.9; 95 % confidence interval 1.65, 14.44; p = 0.001) were associated with high-risk landings. CONCLUSIONS: Jockeys who ride in lower race classes, who hung onto the reins before landing, and who didn't tuck-and-roll during a fall had increased risk of a high-risk landing. Further examination of relationships between race, jockey experience and fall behaviour characteristics upon injury outcomes, and evaluation of potential protective benefits of fall training are required.

Segmental sequencing of the upper body segments in unconstrained maximum overarm throws: An implication for coaching.

Overarm throwing is an essential fundamental movement skill (FMS). Competency in throwing is critical to encourage physical activity throughout lifespan. However, the segmental sequencing characteristics of skilled throwing to achieve maximum ball release speed are unclear. Further, the standard instructions for segmental sequencing in coaching manuals are anecdotal and not based on scientific evidence. Therefore, the aim of this study was to establish the critical features of upper-body sequencing in skilled throwing for maximum speed. This would enable revised instructions for coaching throwing based on scientific evidence. The three-dimensional kinematics of 144 right-handed unconstrained maximum overarm throws were captured and analyzed. The quartiles of participants with the fastest and lowest ball release speed, normalized by height, were defined as the Skilled Group and Less Skilled Group, respectively. Paired t-tests were used to determine the differences in times of successive events within groups and independent t-tests for between-group differences in temporal space between events for all sequences. A characteristic segmental sequence of each group was defined as a sequence with significant within-group differences in two successive events (p < 0.001), while a critical segmental sequence was defined as a sequence with significant differences in temporal space both within groups and between groups (p < 0.001). The Skilled Group had six characteristic sequences, while two were found for the Less Skilled Group, summarized in the conceptual model. A single critical sequence of non-throwing arm elbow extension prior to shoulder extension was found. Five evidence-based instructions were recommended to add to the Australian FMS instruction manual.

Player-labelling as a solution to overcome maturation selection biases in youth football.

The fact that potentially skilled, but biologically later-maturing athletes are less likely to be selected into talent development programmes (TDP) can represent a failure of Talent Identification (TID) in sports. To overcome maturation selection biases, maturation independent TID should be established to include less mature, but talented athletes in TDP more frequently. Using a randomised parallel-group design, this study aimed to evaluate the effect of labelling under-11 (U11) Swiss male youth football players (n = 24, age = 11.0 ± 0.3 years) via maturation-ordered shirt numbers during rank assessment by talent scouts (n = 83, scout experience = 4.8 ± 2.4 years). Following observation of video recorded selection tournaments, player-labelling "informed" scouts were significantly more likely to rank less mature players higher on their player potential, t(81) = 2.57, p = .012, d = -0.6, 95% CI [-1.00, -0.13], than "uninformed" scouts. As altered rankings assisted less mature players, player-labelling may offer a practical and feasible strategy to improve TID by removing possible maturation selection biases. To address maturation selection biases and the potential positive impact of player-labelling more broadly, further research on both male and female athletes in various age categories and sports contexts is recommended.

Corrective Adjustment Procedures as a strategy to remove Relative Age Effects: Validation across male and female age-group long jumping.

OBJECTIVES: To validate the application of Corrective Adjustment Procedures for removing Relative Age Effects in youth athletic contexts, this study estimated the longitudinal relationships between decimal age (chronological and relative) and performance in male and female long jumpers. Using trendlines, Corrective Adjustment Procedures were applied, and Relative Age Effect distributions associated with performance attainment were re-examined. DESIGN: Retrospective longitudinal design examining competitive long-jump data between 2005 and 2019. METHODS: In Part I, participants were 689 junior Italian long jumpers (age range = 11.01-17.99 years; 56.6% females) who participated in ≥three events. Longitudinal modelling and regression equations quantified the sex-specific relationships between decimal age and long jump performance. In Part II, equations were utilised to adjust individual performance within an independent sample (N = 13,639; 50.1% females) of age-matched jumpers. Relative Age Effect distributions within attainment levels (i.e., Top 25-10%) were examined based on raw and correctively adjusted performance. RESULTS: Irrespective of sex, Relative Age Effects were prevalent across all age-groups with medium-large effect sizes at 12-17 (males and females) and 12-17 years (females) of age (Cramer's V range = 0.07-0.28). Relative Age Effect bias magnitude also increased with attainment level (i.e., Top 25-10%). Following Corrective Adjustment Procedure application, typical Relative Age Effects were removed with non-significant deviations in relative age distributions regardless of sex or age-group or attainment level (Top 25 or 10%). CONCLUSIONS: Findings provide efficacy for Corrective Adjustment Procedure application to remove Relative Age Effects across youth long jumping events. Corrective Adjustment Procedures suggest potential in improving performance evaluation, identification of technically skilled performers, and sporting experiences.

Understanding the Role of Propulsion in the Prediction of Front-Crawl Swimming Velocity and in the Relationship Between Stroke Frequency and Stroke Length.

Introduction: This study aimed to: 1) determine swimming velocity based on a set of anthropometric, kinematic, and kinetic variables, and; 2) understand the stroke frequency (SF)-stroke length (SL) combinations associated with swimming velocity and propulsion in young sprint swimmers. Methods: 38 swimmers (22 males: 15.92 ± 0.75 years; 16 females: 14.99 ± 1.06 years) participated and underwent anthropometric, kinematic, and kinetic variables assessment. Exploratory associations between SL and SF on swimming velocity were explored using two two-way ANOVA (independent for males and females). Swimming velocity was determined using multilevel modeling. Results: The prediction of swimming velocity revealed a significant sex effect. Height, underwater stroke time, and mean propulsion of the dominant limb were predictors of swimming velocity. For both sexes, swimming velocity suggested that SL presented a significant variation (males: F = 8.20, p < 0.001, η2 = 0.40; females: F = 18.23, p < 0.001, η2 = 0.39), as well as SF (males: F = 38.20, p < 0.001, η2 = 0.47; females: F = 83.04, p < 0.001, η2 = 0.51). The interaction between SL and SF was significant for females (F = 8.00, p = 0.001, η2 = 0.05), but not for males (F = 1.60, p = 0.172, η2 = 0.04). The optimal SF-SL combination suggested a SF of 0.80 Hz and a SL of 2.20 m (swimming velocity: 1.75 m s-1), and a SF of 0.80 Hz and a SL of 1.90 m (swimming velocity: 1.56 m s-1) for males and females, respectively. The propulsion in both sexes showed the same trend in SL, but not in SF (i.e., non-significant variation). Also, a non-significant interaction between SL and SF was observed (males: F = 0.77, p = 0.601, η2 = 0.05; females: F = 1.48, p = 0.242, η2 = 0.05). Conclusion: Swimming velocity was predicted by an interaction of anthropometrics, kinematics, and kinetics. Faster velocities in young sprinters of both sexes were achieved by an optimal combination of SF-SL. The same trend was shown by the propulsion data. The highest propulsion was not necessarily associated with higher velocity achievement.

Effect of bio-banding on physiological and technical-tactical key performance indicators in youth elite soccer.

Bio-banding has been introduced to reduce the impact of inter-individual differences due to biological maturation among youth athletes. Existing studies in youth soccer have generally examined the pilot-testing application of bio-banding. This is the first study that investigated whether bio-banded (BB) versus chronological age (CA) competition affects reliable physiological and technical-tactical in-game key performance indicators (KPIs) using a randomized cross-over repeated measures design. Sixty-five youth elite soccer players from the under-13 (U13) and under-14 (U14) age category and with maturity offsets (MO) between -2.5 and 0.5 years, competed in both a BB and CA game. For statistical analysis, players were divided into four sub-groups according to CA and MO: U13MOlow (CA ≤ 12.7, MO ≤ -1.4), U13MOhigh (CA ≤ 12.7, MO > -1.4), U14MOlow (CA > 12.7, MO ≤ -1.4), U14MOhigh (CA > 12.7, MO > -1.4). The two-factor mixed ANOVA revealed significant (p < .05) interactions between competition format and sub-group for the KPIs high accelerations (ηp2 = .176), conquered balls (ηp2 = .227) and attack balls (ηp2 = .146). Especially, U13MOhigh (i.e. early maturing players) faced a higher physiological challenge by having more high accelerations (|d| = 0.6) in BB games. Notably, U14MOlow (i.e. late maturing players) had more opportunities to show their technical-tactical abilities during BB games with more conquered balls (|d| = 1.1) and attack balls (|d| = 1.6). Affected KPIs indicate new challenges and learning opportunities during BB competition depending on a player's individual maturity status. Bio-banding can beneficially be applied to enhance the talent development of youth elite soccer players.

Development of a video analysis protocol and assessment of fall characteristics in equestrian cross-country eventing.

Cross-country eventing is one of the highest-risk sporting activities for serious injury outcomes. This study investigated relationships between fall characteristics and high-risk falls at jumps in cross-country eventing. A video analysis protocol was systematically developed to analyze 87 video recordings of high-risk rider falls; defined as when the rider's head impacted the ground and/or where there was potential horse impact with the rider. Falls were classified according to competition type, jump type, horse-related, and rider-related factors. At least one high-risk fall characteristic was observed in 45 of 87 examined falls. Multivariable best subsets regression identified five independent variables explaining 38.4% of the variance in the number of high-risk falls. Increased likelihood of high-risk falls was associated with continuation of horse direction or speed upon rider ground impact, higher jump approach speed, changes in rider body posture upon landing, rider air jacket usage, and reduced rider fall time. The Eventing Fall Assessment Instrument (EFAI) video analysis protocol (attached as supplementary material) facilitated systematic examination of multiple characteristics associated with high-risk falls and identified likely influential characteristics. Based on EFAI and subsequent data analyses, findings suggest optimized approach speed for correct striding and take-off; jump design to enable run-out; and rider training could help reduce the occurrence of high-risk falls. Air jacket usage and their design characteristics warrant further investigation.

How Relative Age Effects Associate with Football Players' Market Values: Indicators of Losing Talent and Wasting Money.

BACKGROUND: In football, annual age-group categorization leads to relative age effects (RAEs) in talent development. Given such trends, relative age may also associate with market values. This study analyzed the relationship between RAEs and market values of youth players. METHODS: Age category, birthdate, and market values of 11,738 youth male football players were obtained from the "transfermarkt.de" database, which delivers a good proxy for real market values. RAEs were calculated using odds ratios (OR) with 95% confidence intervals (95%CI). RESULTS: Significant RAEs were found across all age-groups (p < 0.05). The largest RAEs occurred in U18 players (Q1 [relatively older] v Q4 [relatively younger] OR = 3.1) ORs decreased with age category, i.e., U19 (2.7), U20 (2.6), U21 (2.4), U22 (2.2), and U23 (1.8). At U19s, Q1 players were associated with significantly higher market values than Q4 players. However, by U21, U22, and U23 RAEs were inversed, with correspondingly higher market values for Q4 players apparent. While large typical RAEs for all playing positions was observed in younger age categories (U18-U20), inversed RAEs were only evident for defenders (small-medium) and for strikers (medium-large) in U21-U23 (not goalkeepers and midfielders). CONCLUSIONS: Assuming an equal distribution of football talent exists across annual cohorts, results indicate the selection and market value of young professional players is dynamic. Findings suggest a potential biased selection, and undervaluing of Q4 players in younger age groups, as their representation and market value increased over time. By contrast, the changing representations and market values of Q1 players suggest initial overvaluing in performance and monetary terms. Therefore, this inefficient talent selection and the accompanying waste of money should be improved.

Longitudinal Relationships Between Maturation, Technical Efficiency, and Performance in Age-Group Swimmers: Improving Swimmer Evaluation.

PURPOSE: The study aimed to (1) accurately examine longitudinal relationships between maturity status and both technical skill indices and performance in Australian male (N = 64) age-group Front-crawl swimmers (10-15 y) and (2) determine whether individual differences in maturation influenced relationships between technical skill level and swimming performance. METHODS: A repeated-measures design was used to assess maturity status and performance on 200-m Front-crawl trial across 2 competition seasons (2018-2020). Assessments were made on 3 to 5 occasions (median = 3) separated by approximately 4 months. Average horizontal velocity and stroke frequency were used to calculate technical skill indices, specifically stroke index, and arm propelling efficiency. Relationships between variables were assessed using linear mixed models, identifying fixed, and random effect estimates. RESULTS: Curvilinear trends best described significant longitudinal relationships between maturity status with horizontal velocity (F = 10.33 [1, 233.77]; P = .002) and stroke index (F = 5.55 [1, 217.9]; P = .02) during 200-m Front-crawl trials. Maturity status was not significantly related to arm propelling efficiency (P = .08). However, arm propelling efficiency was an independent predictor of Front-crawl velocity (F = 55.89 [1, 210.45]; P < .001). CONCLUSIONS: Maturity status predicted assessment of swimmer technical skill (stroke index) and swimming performance. However, technical skill accessed via arm propelling efficiency was independent of maturation and was predictive of performance. Maturity status influences performance evaluation based on technical skill and velocity. Findings highlight the need to account for maturation and technical skill in age-group swimmers to better inform swimmer evaluation.

Assessing the Ecological-Context Strengths of School-Based Talent Development Programs in Rugby League.

Purpose: Adopting an ecological perspective, the study explored the context-strengths of three successful school-based TDEs in rugby league. Method: Utilizing a mixed methods approach, incorporating validated psychometric questionnaires (N = 118) and semi-structured interviews, various stakeholder perspectives (N = 30; i.e., current/past students and coaches) were triangulated and corroborated to identify TDE ecological strengths. Results: Compared to benchmark TDE data, and supplemented by descriptions of TDE features and processes, results confirmed strong coherence to "effective" factors in TDE literature. Collective "ecological strengths" included quantitative findings of a highly supportive culture, shared "person" and "athlete" desired outcomes, and a long-term focus; and qualitative features of high behavioral expectations, strong values of hard work, and the promotion of personal ownership in athlete development. Opportunities to enhance TDE effectiveness were also identified, with psychological skill development (e.g., self-reflection, coping) and balancing intra-rugby league pathway demands (i.e., competition/training loads) highlighted. Conclusion: Findings identify characteristics, components, and processes of school-TDE environments associated with successful athlete development in schools and beyond (i.e., transition into an athlete development pathway).

Maturity-related developmental inequalities in age-group swimming: The testing of 'Mat-CAPs' for their removal.

OBJECTIVES: To (1) examine the association between maturity timing and performance-based selection levels in (N=708) Australian male 100-m Freestyle swimmers (12-17 years); (2) identify the relationship between maturation status and 100-m Freestyle performance; and (3) determine whether Maturation-based Corrective Adjustment Procedures (Mat-CAPs) could remove maturation-related differences in swimming performance. METHODS: In Part 1, maturity timing category distributions ('Early', 'Early Normative', 'Late Normative' and 'Late') for 'All', 'Top 50%' and '25%' of raw swimming times were examined within and across age-groups. In Part 2, multiple regression analyses quantified the relationship between maturity offset (YPHV) and swimming performance. In Part 3, sample-based maturity timing category distributions were examined based on raw and correctively adjusted swim times for 12-17 year old age-groups. RESULTS: Based on raw swim times, a high prevalence of 'Early-maturing' swimmers, with large effect sizes was identified (e.g., 14 years 'All' - χ2 (3, 151=111.98, p<0.001; 'Early' v 'Late' OR=82.0 95%CI=4.77, 1409.9); while a complete absence of 'Late-maturers' was apparent in the sample (N=708). When maturity categories were re-defined based on sample mean±standard deviation, and when using the expected curvilinear trendline identified in Part 2, Mat-CAPs mitigated maturity timing biases across all age-groups and selection levels, and removed the Freestyle performance advantage afforded by advanced maturity timing and status. CONCLUSIONS: Removing the influence of maturation-related developmental differences could help improve youth swimmer participation experiences and improve the accuracy of identifying genuinely skilled age-group swimmers.

Sink or Swim? A survival analysis of sport dropout in Australian youth swimmers.

OBJECTIVES: To examine long-term participation and dropout rates in Australian youth swimming using survival analyses and to determine whether multiple individual, socio-demographic, and competition-related factors influenced dropout. DESIGN: Retrospective cohort study of registration and competitive performance data. METHODS: Part 1-Registration data from N = 17 161 female (n = 9400) and male (n = 7761) New South Wales (NSW) swimmers aged 10-15 years (inclusive). Part 2-Competition level involvement in a subsample of female (n = 1011) and male (n = 811) swimmers, aged 12-15 years, was also examined. To determine dropout rates and influential factors, Kaplan-Meier survival analyses supplemented by Cox regression were used. RESULTS: (1) Kaplan-Meier analyses identified median sustained participation rates of four years (95% CI = 3.93-4.06), with 15.9% maintaining participation over 10 years. Cox regressions identified age-group was associated with dropout (P < .001), with a 184.9% higher Hazard Rate (HR) for 10- vs 15-year-olds. Residential proximity to major cities was associated with dropout (P < .001), with urban swimmers reporting a 24.8% higher HR rate than rural swimmers. Sex and relative age were not associated with dropout. (2) The subsample median sustained participation was five years (95% CI = 4.79-5.20), with 25.3% maintaining participation for ten years. Level of competition was associated (P < .001), with an 86% higher HR when considering lower competition levels (ie, club/district v national). CONCLUSION: In a large representative sample of swimmers, survival analyses identified age-group, competition level, and city proximity were associated with increased swimming dropout rates.