Search Results (144)

Background: Estimating race times for open-water swimming based on pool swimming times could be useful for talent identification and training optimisation. We aimed to compare the swimming speeds of the world’s top and other swimmers in the 2023 Aquatics Championship men’s 10 km OWS race. Methods: Sixty-five swimmers were divided into four groups: G1 (1st–10th positions), G2 (11st–30th positions), G3 (31st–47th positions), and G4 (48th–65th positions). Swimming speed, stroke frequency (SF), and stroke length (SL) for each lap (laps 1–6) were recorded. Critical speed (CS) was calculated from each participant’s personal best times in the 400, 800, and 1500 m freestyle events in the pool. Swimming speed against CS was calculated (%CS). Results: The top performance group (G1) maintained their swimming speed from beginning (lap 1, 1.53 m/s) to end (lap 6, 1.50 m/s), at 92.7 ± 1.9% of CS, characterised by longer SL (1.26 m) and lower SF (72.86 rpm). G3 and G4 were unable to maintain their swimming speed, which decreased from G3: 97.64 ± 1.62% and G4: 96.10 ± 1.96% of CS at lap 1 to G3: 88.39 ± 3.78% and G4: 85.13 ± 5.04% at lap 6. This reduction in swimming speed is consistent with the increased reliance on anaerobic metabolism reported in previous studies under similar conditions. Conclusions: Race pacing for maintaining speeds of 92%CS throughout the race could be an important resilient index in open-water swimming. %CS might be a useful index for estimating the athletic performance level in open-water swimming. Full article

Tennis is a demanding sport that requires physical abilities and optimal body composition. The aim of this study was to investigate the anthropometric characteristics, body composition, and somatotype development of young Slovenian tennis players (754 boys and 514 girls aged 12 to 18 years) over the last two decades. Using standardised anthropometric measurements and the Heath-Carter method, somatotypes were calculated and analysed by age and gender. The results showed clear age- and gender-specific trends and differences in both somatotype profiles and detailed anthropometric characteristics. Significant differences were found in height, body mass, BMI, skinfolds, girths, and limb lengths, with gender differences becoming more pronounced in the older age groups. In boys, mesomorphy increased with age, reflecting an increase in musculature, while in girls, a shift from ectomorphic to endomorphic profiles was observed during adolescence, probably influenced by pubertal and hormonal changes. Significant sex-specific differences were observed in all three somatotype components in most age groups, especially in fat mass and muscle. The longitudinal design provides valuable data and insights into the evolving physical profiles of adolescent tennis players that support more effective talent identification and training. Despite the changes that have taken place in tennis over time, standardised measurement protocols ensured comparability, making the results relevant for practitioners working with adolescents in tennis development. Full article

The Relative Age Effect (RAE) refers to the advantage that relatively older athletes within the same age group may have in sports. While this phenomenon has been widely documented in numerous disciplines, its presence in orienteering remains largely unexplored. This study aimed to analyse the existence of RAE among Spanish orienteers selected for international competitions organised by the International Orienteering Federation (IOF) between 1987 and 2023. A total of 384 participations (225 male, 159 female) were examined across the European Youth Orienteering Championships (EYOC), Junior World Orienteering Championships (JWOC), and the European and World Orienteering Championships (EOC + WOC). The distribution of birth dates by quartiles and semesters was compared using chi-square tests, Cramér’s V, Z-tests, and odds ratios with 95% confidence intervals. The results revealed a significant RAE in male athletes, particularly in JWOC, where those born in the first quartile were up to 3.77 times more likely to be selected than those in the third quartile. In contrast, no significant associations were found in female athletes, which may reflect structural or developmental differences related to sex. These gender-based disparities highlight the importance of integrating sex-specific considerations into selection policies. Overall, the findings suggest a selection bias favouring relatively older males, which may hinder the development of late-born talent. Therefore, it is recommended that selection criteria be reassessed to ensure fairer and more inclusive talent identification and development in youth and elite orienteering. Full article

This study aimed to describe the training leading to the Zwift Academy (ZA) Finals of a world-class road cyclist who earned a professional contract after winning the contest. Four years of daily power meter data were analyzed (male, 25 years old, 68 kg, VO₂max: 85 mL·min⁻¹·kg⁻¹, and 20-min power: 6.37 W·kg⁻¹), focusing on load, volume, intensity, and strategies. Early training alternated between long, moderate-intensity sessions and shorter high-intensity sessions, with easy days in between. Gradually, the structure was progressively modified by increasing the duration of moderate-intensity (MIT) and high-intensity (HIT) and, subsequently, moving them to “high-volume days”, creating a sort of “all-in days” with low-intensity (LIT), MIT, and HIT. Moderate use of indoor training and a few double low-volume, low-intensity sessions were noted. These data provide a deep view of a 4-year preparation period of ZA, providing suggestions for talent identification and training, thereby highlighting the importance of gradual progression in MIT and HIT. Full article

The relative age effect (RAE) refers to the advantage often observed in sports selection processes, where athletes born earlier in the calendar year are favored over those born later. While the RAE has been widely studied in various sports, little is known about its presence in rhythmic gymnastics (RG), a female-dominated esthetic sport characterized by early specialization. This study investigated the presence of the RAE among elite rhythmic gymnasts (RGs) at the international level, focusing on differences in birth quarter distribution across age categories and performance levels. The sample included 578 RGs—356 juniors and 222 seniors—competing in individual and group events. Birthdates were categorized into four quartiles (Q1–Q4). Chi-square goodness-of-fit tests and standardized residuals as post hoc tests were used to analyze the RAE. No significant RAE was found in the overall sample or when analyzed by geographic region (p > 0.05). However, a significant under-representation in Q4 occurred for Group RGs (SR = −2.17), and among all juniors (SR = −2.54) (χ²[3, 356] = 9.833, p < 0.05, w = 0.17), particularly in the subgroup of 15-year-old gymnasts, who were over-represented in Q3 (SR = 2.55; χ²[3, 183] = 10.027, p < 0.05, w = 0.23). Finalists—especially those in group events—also showed a higher proportion of Q3 athletes and a lower proportion of those born in Q4. Among junior finalists, Q4 was significantly under-represented (p < 0.05). These novel sport-specific findings suggest the presence of an atypical RAE pattern in RG, particularly in younger age groups and among high-performing athletes. RG coaches and policymakers should consider alternative selection models and adapt training approaches for Q4-born gymnasts in order to prevent early deselection. Full article

(1) Background: Research examining the combined influence of anthropometric characteristics, chronological age, and training age on motor performance in handball is limited. Given the sport’s demands and the participation of both adolescent and adult athletes, understanding these relationships is essential for talent identification, personalized training, and long-term athlete development. This study aimed to explore how these variables affect motor performance indicators such as speed, agility, and explosive power. (2) Methods: A cross-sectional study was conducted involving 29 male handball players. Anthropometric data (height and body weight), chronological age, and training age were collected. Motor performance was assessed using a 30 m sprint, a vertical jump test, and an agility test. (3) Results: Chronological age showed a strong positive correlation with training age (r = 0.819), and moderate correlations with height, body weight, vertical jump, agility, and sprint time. Training age was moderately correlated with vertical jump (r = 0.465) and agility (r = 0.439). Height and body weight were positively associated with sprint time. BMI exhibited low but consistent correlations with all motor tests. Regression analysis revealed that height significantly predicted sprint performance (β = 0.401, p = 0.033), while BMI was not a significant predictor. No significant regression models were found for agility or vertical jump performance. (4) Conclusions: The results suggest that both chronological and training age influence certain aspects of motor performance in handball players. Height may serve as a useful predictor of sprint ability, but anthropometric indicators such as BMI appear insufficient for explaining performance in agility or explosive power tasks. These findings support the use of multidimensional and individualized approaches in athletic assessment and training design. Full article

Amid China’s “dual carbon” goals of achieving carbon peaking and carbon neutrality, understanding the spatial dynamics of carbon emissions is essential for promoting coordinated regional decarbonization. This study takes a systems perspective to investigate the drivers and network structures of carbon emissions across 31 Chinese provinces from 2000 to 2022. Utilizing a Spatial Durbin Model (SDM) alongside social network analysis (SNA), it examines both the spatial spillover effects of key economic and innovation-related factors and the structural characteristics of interprovincial carbon transmission networks. The main findings include the following: (1) a significant spatial autocorrelation in provincial carbon emissions, indicating strong cross-regional spillover effects; (2) a nonlinear, inverted U-shaped relationship between green innovation and carbon emissions, where emissions initially rise before declining as innovation matures; (3) a dual impact of human capital, which increases local emissions but reduces emissions in neighboring regions through knowledge diffusion; and (4) the identification of key provinces such as Shaanxi, Henan and Hubei as central nodes within the carbon emission network, acting as influential hubs in the transmission of carbon emissions. This study highlights the importance of differentiated policy design based on regional network centrality and advocates for a systemic governance framework that promotes technology diffusion, talent mobility, and collaborative emission control across provinces. The integrated SDM-SNA approach provides a novel perspective for understanding the complexity of carbon governance in large economies and offers a flexible framework that can be adapted to other national or subnational settings. Full article

Objectives: The study aims to compare three distinct protocols—Moore, Mirwald, and the new BAUSport^TM SonicBone system—for predicting somatic maturation in youth athletes. Methods: The participants were female members of the Croatian national volleyball youth team (U-17) (n = 16). The study involved comprehensive measurements, including height, weight, sitting height, leg length, wrist diameter, hand joint diameter, hand grip strength, and ultrasound measurements for skeletal age assessment. Results: Correlation analysis showed moderate to strong correlations between the Moore and Mirwald skeletal age estimates, but both showed weaker correlations with the BAUSport^TM skeletal age. Repeated-measures ANOVA showed no significant difference between the Moore and Mirwald methods (p > 0.05); significant differences between both the Moore and Mirwald methods and the BAUSport^TM method (p < 0.05). Regression analysis revealed that height, weight, sitting height, leg length, wrist diameter, and hand joint diameter explained 69% of BAUSport^TM, with wrist diameter being the only significant predictor. While the Moore and Mirwald methods remain useful tools for estimating the timing of an athlete’s growth spurt, BAUSport^TM represents a potential advancement in skeletal age assessment. Further research is needed to validate BAUSport^TM across diverse populations and optimize its calibration to accommodate anatomical variations. Conclusions: The findings suggest that with further refinement, BAUSport^TM could become a new standard for monitoring skeletal development in youth athletes. Additionally, studies should explore comparative analyses with other emerging technologies, such as genetic markers, hormonal assessments, and MRI, for further understanding of biological maturation in talent identification. Full article

Background: Maturation is a complex biological process affecting all tissues, organs, and systems, particularly during adolescence. The Peak Height Velocity (PHV) period, a hallmark of adolescent growth spurts, is associated with individual differentiations in the development of performance attributes amongst youth. Understanding the influence of sports participation on strength and power during the PHV period is essential for optimizing training outcomes and reducing injury risk. This scoping review synthesizes the literature on the strength and power development in athletes during the PHV period across various sports, highlighting the interaction between maturation, training, and performance outcomes. Methods: A systematic search of PubMed and Scopus, supplemented by manual searches, identified peer-reviewed studies from 2004 to 2025. The included longitudinal studies involved structured training and assessed strength-related performance during and around the PHV period. PRISMA-ScR guidelines were followed. Results: Twelve studies met the inclusion criteria. It is found that strength and power are significantly affected during the PHV period and participation in sports mitigates these effects. Training characteristics such as training frequency/volume and sport specificity were key factors. Early maturers often outperformed late maturers, though adolescent awkwardness temporarily reduced performance around PHV. Conclusions: Systematic participation in sports training can limit the phenomenon of adolescent awkwardness in the performance of strength and power. Hence, training programs should be tailored to maturity status, emphasizing skill development, strength training, and injury prevention. Future research should explore individualized training and the mechanisms underlying performance variability during the PHV period. Full article

Objective: This study aimed to investigate the effect of relative age on gross motor coordination (GMC) development, taking into account biological maturity and sex. Methods: 729 participants aged 10 to 16 years completed three GMC tests newly designed to minimize the potentially confounding effects of physical fitness. The tests included a Hand-Foot coordination test, Dribbling-Targeting test (DT test), and a T balance and agility test (T test). Relative age was determined using birth quartiles: BQ₁ (January–March); BQ₂ (April–June); BQ₃ (July–September); and BQ₄ (October–December). Regarding biological maturity, the participants were categorized according to their estimated peak height velocity (pre- and post-PHV). Results: Relative age did not significantly impact the overall GMC score. In contrast, biological maturity emerged as a significant determinant of GMC, with post-PHV participants outperforming their pre-PHV counterparts in the three tests (p < 0.001). The results also showed a significant main effect of sex in the DT and T tests, i.e., in tasks involving dynamic coordination and agility, with boys consistently outperforming girls (p < 0.001). Significant biological maturity × sex interactions in the DT and T tests also indicated an advantage of boys over girls with advancing biological maturity (p < 0.05). Conclusions: these findings highlight the importance of considering biological maturity and sex rather than relative age in GMC development from childhood through adolescence. Full article

Objectives: Water polo players ought to possess various physical capacities and well-developed cognitive functions that reflect the requirements of their specific playing position. Therefore, the objective of this study was to compare the cognitive performance, anthropometric characteristics and specific swimming capacities of youth water polo players in different playing positions. Methods: The present cross-sectional study involved 106 youth water polo players. The subjects were recruited as part of a project for talent identification and selection for the Croatian National Water Polo Team. Testing included anthropometric measurements, specific swimming capacities and cognitive performance (Stroop test). Results: Among the 106 youth water polo players, there were 15 goalkeepers (14.2%), 21 center-defenders (19.8%), 17 center-forwards (16.0%), 34 drivers (32.1%) and 19 wings (17.9%), with the mean age of 14.14 ± 0.38 years. The wings performed faster than center-forwards in both StroopOff time (wings: 57.14 ± 10.04 s vs. center-forwards: 67.03 ± 9.72 s, p = 0.016) and StroopOn time (wings: 66.18 ± 15.86 s vs. center-forwards: 80.24 ± 15.64 s, p = 0.019). Conclusions: In conclusion, this study demonstrated significant differences between different playing positions in youth water polo players, specifically between center-forwards and wings. They performed faster than center-forwards in all tested variables of the Stroop test, measures of psychomotor ability, response inhibition and motor speed, as well as in specific swimming capacities measured in the 50 m crawl and the 400 m crawl. The results of this study provide a valuable foundation for establishing developmental recommendations for different playing positions, aimed at improving player’s performance. These recommendations should take into account anthropometric characteristics, specific functional swimming capacities and cognitive functions that influence players’ game intelligence, which can be enhanced through properly designed training programs. Full article

Youth soccer academies are dominated by the older players in each annual age cohort because they are judged to be better at the time of selection. Failing to identify talented players because they are simply younger in their cohort is a problem of both discrimination and poor practice. One potential method for addressing such biases is to develop and use age- and size-corrected assessments of individual players using traits closely associated with match success. In this study, we quantified the relationship between age and size with individual passing and control performance in six different tests for 170 players between 10 and 20 years old from a Tier 1 academy in Brazil. Passing tests were significantly repeatable and performance varied among tests (df = 5; F = 432.2; p < 0.001). Overall passing performance (PC_P1)—based on all tests—was significantly positively associated with age (R² = 0.42, t = 10.67; p < 0.001), height (R² = 0.19, t = 6.13; p < 0.001) and mass (R² = 0.23, t = 6.90, p < 0.001). In addition, tests of passing and control could discriminate among groups of differing playing levels (test 1: F_(2,116) = 55.2, p < 0.001; test 3: F_(2,116) = 12.0, p < 0.001). Normative algorithms from this study can be used to compare athletes during selection trials and against an elite group, after taking age and size into account, and using such algorithms could vastly reduce the insipid age-biases that plague youth football. Full article

This study presents a comprehensive bibliometric analysis of growth and maturation (GAM) research in youth basketball. A systematic search of Web of Science (up to August 2024) identified 1160 records; after screening per bibliometric review guidelines, 141 relevant studies were selected. Descriptive analysis indicates an 11.59% annual increase in GAM publications since 2003, underscoring significant expansion of this field. The 576 authors contributing to these studies show a high degree of collaboration, averaging 5.42 co-authors per paper, and 52.60% of publications involve international partnerships. Citation network analysis reveals that GAM research on basketball players predominantly addresses sports performance, strength, and injuries. Core themes (e.g., maturity/maturation) are well integrated, while foundational topics such as growth, strength, and age, although central to the field, remain underexplored. These gaps highlight the need for more targeted investigations. Practically, the findings guide coaches, trainers, and sports administrators in designing developmentally appropriate training programs, implementing targeted injury-prevention strategies, and refining talent identification initiatives. By identifying key areas for further inquiry, this study seeks to strengthen youth basketball programs through growth-stage-specific training methods, optimized injury-prevention protocols, and a holistic approach to athlete development. Full article

Background: This cross-sectional study aims to clarify the relationship between coaches’ decisions and players’ relative age, biological maturation, and experience when identifying Under-14 (U14) players for the District and National Teams. Methods: A total of 360 male soccer players participating in the U14 national inter-association tournament, Lopes da Silva, were assessed. Birth dates were recorded, and players were categorized by birth quarter. Anthropometric measurements, fitness level (handgrip strength), and success indicators (performance evaluated by the coach, minutes played, and selection for the National Team) were documented, Maturation status was determined using bone age. Results: The majority of the sample was born in the 1st and 2nd quartiles regardless of maturation status. Morphological and functional differences between players born in different quartiles were no longer significant after controlling the effect of bone age. Late-maturing athletes played significantly fewer minutes. Among the players selected for the National Team, 89.9% were early or on-time maturers, and 92.9% were born in the first or second quartile of the year. While previous studies have shown reduced variability between bone and decimal age in the third and fourth quartiles, our findings indicate greater variability across all birth quartiles. Conclusions: Maturation status and relative age effect are crucial factors influencing coaches’ selection decisions. These findings highlight the need for a more equitable approach to talent identification, which should include track maturation bias avoiding the pursuit of short-term success and promoting long-term development programs for young soccer players. Undoubtedly, maturation status and relative age effect (RAE) play a significant role in a coach’s decision-making process. Full article

This study investigates the relative age effect (RAE) in Spanish orienteering, comparing birth distributions between the general population and federated athletes, as well as across different age groups. A cross-sectional and retrospective observational analysis was conducted on data from 34,718 athletes federated (female: n = 12,338; male: n = 22,380) with the Spanish Orienteering Federation (FEDO) between 2005 and 2023. Birth distributions by quartiles and semesters were compared with birth data from the Spanish National Institute of Statistics. Chi-square tests, Z-tests for proportions, and odds ratio (OR) analysis were used to assess differences and the magnitude of the RAE. A significant RAE was found in the total population of federated athletes and the youth and male elite subgroups, with an over-representation of athletes born in the first semester of the year. The effect was small in magnitude but persistent in youth categories and intensified in the male elite category. In contrast, no significant RAE was observed in the female elite category. The RAE exists in Spanish orienteering, although its magnitude is smaller compared to other sports. The persistence of the RAE in the male elite category suggests that advantages accumulated in formative stages influence access to higher levels. Strategies to mitigate the impact of the RAE in talent identification and development are recommended. Full article