Ahlan Benezar Lima

Background: Understanding how physical fitness develops during adolescence is critical for interpreting and optimizing training and setting realistic performance expectations in youth sport. Yet, evidence-based, age-referenced benchmarks that track multiple fitness components across sports remain lacking, leaving practitioners without reliable normative trajectories to guide athlete development. Purpose: This longitudinal meta-analysis estimated developmental trajectories for vertical jump, sprint, and endurance performance in male youth athletes across multiple sports using data from longitudinal studies. Methods: Following PRISMA guidelines, we conducted a systematic search of MEDLINE, Web of Science, and Scopus for studies with repeated measurements of vertical jump, 10-meter sprint, and endurance performance in male youth athletes, from database inception to October 4, 2025. Analyses were restricted to males due to an insufficient number of eligible studies including female athletes. We applied a risk-of-bias assessment adapted from the Cochrane risk-of-bias tool and examined publication bias through funnel plot inspection and Egger’s regression test. We used Bayesian multilevel growth curve modeling to estimate age-related developmental trajectories, with analyses stratified by sport and test protocol. Results: Twenty-eight studies met eligibility criteria, providing 41 independent samples across nine sports. Vertical jump and endurance performance exhibited curvilinear trajectories with peak velocity occurring at 13.2 years (68% CrI [±1 posterior SD]: 13.0; 13.5) and 13.8 years (68% CrI: 13.6; 14.2), respectively, overlapping the typical period of peak height velocity in male athletes. Sprint performance showed linear improvement throughout adolescence (ages 12–17) without distinct acceleration periods. Sport-specific analyses revealed varying absolute values but broadly similar developmental patterns within each fitness component, with rugby exhibiting the highest vertical jump values and minimal sport differences observed for sprint development. Conclusion: The present age-referenced trajectories offer practical benchmarks for monitoring progression and setting realistic expectations in youth sport contexts. Our findings reveal distinct developmental patterns—curvilinear trajectories for vertical jump and endurance with peak improvements around ages 13–14 versus linear progression for sprint—with peak velocities coinciding with typical maturation timing Trial registration : CRD42020175084 (PROSPERO) 25/03/2020.

Meta-analysis in sports science has predominantly focused on cross-sectional comparisons, leaving the temporal structure of longitudinal evidence largely unexploited. This tutorial introduces Bayesian hierarchical longitudinal meta-analysis as a principled framework for synthesizing repeated-measures data and illustrates its implementation using the R package `brms`. We demonstrate a complete analytical workflow---from model specification and prior selection to convergence checks, posterior predictive checks, and reporting—using a simulated dataset based on pubertal stature growth in male youth athletes. The worked example highlights how polynomial growth models recover biologically meaningful parameters, such as age at peak height velocity, with full uncertainty quantification. Additionally, we compare three prior specifications using leave-one-out cross-validation to test robustness. Fully annotated code scripts are provided, providing researchers with the practical tools and methodological reasoning necessary to apply longitudinal Bayesian meta-analysis to their own work in sports science and related fields.

This study examined developmental trajectories of vertical jump performance in young female basketball and volleyball players using Bayesian multilevel modeling. Eighty-one Brazilian female athletes (basketball: n = 46; volleyball: n = 35) aged 11-18 years were assessed between 2016-2024 in a mixed longitudinal design. Models examined longitudinal age-related changes in countermovement jump performance, sport-specific differences, and body size effects. Results showed non-linear developmental patterns with accelerated improvement during early-to-mid adolescence followed by deceleration. Sport differences emerged in baseline performance levels rather than timing. Age effects strengthened after adjusting for body size ( β age = 0.25, 68% credible interval [CI]: 0.17, 0.34; β age 2 = -0.18, 68% CI: -0.28, -0.08), indicating neuromuscular adaptations distinct from increases in body size. Body mass negatively associated with jump performance ( β body mass = -0.35, 68% CI: -0.44, -0.25), while stature positively associated ( β s t a t u r e = 0.20, 68% CI: 0.10, 0.29). Volleyball players demonstrated lower baseline performance than basketball players ( β v o l l e y b a l l = -0.35, 68% CI: -0.43, -0.27). Substantial between-athlete variability in baseline performance ( σ i n t e r c e p t = 0.31) suggests limited predictive validity of early assessments. Our findings provide substantial female-specific evidence for developmental patterns in youth team sport athletes and demonstrate the utility of Bayesian methods for handling incomplete longitudinal data.

Resumo: Com o objetivo de analisar os motivos que acarretam o abandono da carreira internacional dos atletas da Seleção Brasileira de Karatê, este estudo adotou uma abordagem de métodos mistos e coletou dados de 47 ex-atletas que fizeram parte desse grupo na categoria sênior. Os participantes responderam a um questionário estruturado com perguntas fechadas e uma pergunta aberta sobre grau de influência dos motivos de abandono da carreira de atleta da Seleção Brasileira. Os dados quantitativos foram analisados por meio de modelos de regressões ordinais multiníveis bayesianos e os dados qualitativos por meio da análise temática. Verificou-se que os motivos que mais influenciaram a saída da Seleção Brasileira foram questões financeiras, dificuldades de conciliação das carreiras e insegurança profissional. Os dois principais temas que emergiram dos comentários dos participantes foram a “falta de uma gestão profissional” e “falta de reconhecimento”. Com base nos resultados, verifica-se a necessidade de uma reestruturação das condições presentes no meio esportivo para que os atletas se sintam seguros em relação à sua carreira e possam performar com excelência.

The present study used a bioecological approach to examine the influence of personal characteristics (maturity status), process (accumulated deliberate practice), and contextual factors (including age group, competition level, sport type, and state) on the variation of sources of enjoyment among young female athletes. We also explored the effect of the dynamic interactions of time with personal characteristics and process (chronological age, menarche age, and years of accumulated deliberate practice in a specific sport). We considered 243 young female athletes (171 basketball players, and 72 volleyball players) aged, on average, 15.0 years (ranging from 10.1 to 19.7 years). Repeated measures were collected from a sub-sample of 84 athletes (41 basketball players, 43 volleyball players) aged, on average, 14.0 years (ranging from 11.5 to 18.1 years) at baseline, across competitive seasons during the survey period to fully operationalize the bioecological approach. Age group, menarche status, onset of specialization, competitive level, sport, state, and self-reported measures of sources of enjoyment, using the Sources of Enjoyment in Youth Sports Questionnaire (SEYSQ), were recorded. We used Bayesian hierarchical models to model the responses of the players in the SEYSQ. The young female athletes mainly agreed (response 5 in the Likert-like scale) with the statements in each factor of the SEYSQ. There was no variation in the responses by SEYSQ factors associated with process (onset of specialization), person (menarcheal status), and context (age group, sport, competitive level, and state), when considering the cross-sectional data. When aligning the three chronosystems (chronological age, menarche age, and accumulated sport-specific deliberate practice), it was possible to identify the importance of the sport context to the changes in the sources of enjoyment across the development of young Brazilian female athletes between 12 and 18 years. Overall, our findings underscore the necessity of incorporating time in ecological approaches to youth sports research through a repeated-measures design to properly operationalize the bioecological approach. The results of the present study do not support the argument that early specialization may lead to low enjoyment and consequent compromise in commitment and sustained participation in youth sports programs.

The present longitudinal meta-analysis aimed to estimate the growth curves and age at peak height velocity (PHV) in young male athletes, considering anthropometric data from available longitudinal studies. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, studies with repeated measurements in young male athletes were identified from searches across four databases (MEDLINE, SPORTDiscus, Web of Science, and SCOPUS). Estimations were based on multilevel polynomial models using a fully Bayesian framework. After a full-text screening of 317 studies meeting the eligibility criteria, 31 studies were considered. Studies were excluded mainly due to study design, repeated reporting, and incomplete reporting of the outcomes. Of the 31 studies analysed, 26 (84%) focused on young European athletes. The average age at PHV for the total sample of studies with young athletes was 13.1 years (90% credible interval: 12.9; 13.4). When considering data by sport, there was substantial variation in the age at PHV estimates (range: 12.4 to 13.5 years). As most studies in the meta-analysis focused on young European football players (52%), predictions for young athletes from other sports may be limited. The age at PHV in the available data occurred earlier than in general paediatric populations.

Background: Early specialization is often assumed to promote quicker and better physical development to attain expertise in sports. This study examined the influence of the specialization onset on the magnitude and patterns of changes in basketball-specific physical fitness within a competitive season, and developmental trends of fitness between 11-17 years in young basketball players. The prior hypothesis was that young basketball players who specialize before pubertal growth (early) would have better physical fitness and develop faster than those who specialize during or after the pubertal growth period. We examined repeated measures of 181 young basketball players (female, n=40; male, n=141). Anthropometry, age, estimated maturity status, and basketball-specific physical fitness (assessed with the countermovement jump, line drill, and yo-yo intermittent recovery level-1 and fitness score) were considered. We grouped players by the onset of specialization as related to biologic maturation milestones (pre-puberty, mid-puberty, and late-puberty specialization). The within-season and developmental changes in physical fitness were fitted using multilevel modeling in a fully Bayesian framework. The fitness outcomes were similar between-player and within-player changes when grouped by specialization across a season. Fitness improvements across a season were apparent for female players, while male players maintained the performance levels. There was no variation in the patterns of physical fitness development between 11-17 years associated with the onset of specialization. Conditional on our data and models, the assumption that early sport specialization provides a physical fitness advantage for future athletic success does not hold. Relevant stakeholders should be conservative in the expectations of development and improvements of physical fitness across a season and adolescence in young basketball players. We provide an operational framework to interpret specialization related to biological maturation milestones.

O objetivo do estudo foi investigar o ambiente de formação inicial percebido por estudantes universitários de Educação Física. Participaram 273 estudantes universitários (Bacharelado n=150; Licenciatura n=123) de uma universidade pública de Santa Catarina (Brasil). Aplicou-se a versão adaptada do Questionário de Avaliação do Ambiente Percebido da Formação Inicial em Educação Física. Realizou-se regressão logística binária para verificar a associação entre as variáveis. Os resultados revelaram que os licenciandos perceberam maior ocorrência de discussões em grupo (OR=2,07), seminários teóricos (OR=1,72), aprendizagem pela prática e desenvolvimento de atitudes reflexivas (OR=1,70) do que os bacharelandos. O ambiente de formação inicial percebido foi similar entre os cursos, mas os licenciandos perceberam mais oportunidades de participação e reflexão.

Brazil has been the benchmark for volleyball performance for at least two decades, providing a unique context to examine expertise development. This study examined the variation in body size, functional capacities, motivation for achievement, competitiveness, and deliberate practice of youth volleyball players associated with differences in biological maturity status, chronological age, and accumulated deliberate volleyball practice, adopting a Bayesian multilevel modeling approach. We considered 68 female and 94 male adolescent players (14.2 years, 90% confidence interval: 12.7 to 16.0). Players were grouped by the onset of deliberate volleyball practice as related to biologic maturation milestones [pre-puberty deliberate practice onset (12% of the sample), mid-puberty deliberate practice onset (51% of the sample), and late-puberty deliberate practice onset (37% of the sample). There was substantial variation in body dimensions and functional performance by gender. There was no variation by gender for motivation for deliberate practice and motivation for achievement and competitiveness. The young volleyball players appeared to be highly motivated and committed to deliberate practice, achievement, and competitiveness. Alignment of chronological age, biological maturation, and accumulated training experience allow more in-depth insights into young volleyball players’ development, providing sounder support for coaches´ decisions.