Understanding fluctuations and associations between swimming performance-related variables provide strategic insights into a swimmer's preparation program. Through network analysis, we verified the relationships between anthropometrics, maturation, and kinematics changes (Δ) in 25-m breaststroke (BREAST) and butterfly (FLY) swimming performance, before and after a 47-week swimming training season. Twenty age-group swimmers (n =11 girls: 10.0 ± 1.3 years and n = 9 boys: 10.5 ± 0.9 years) performed a 25-m all-out swim test (T25) in BREAST and FLY techniques, before and after 47 weeks. Three measures of centrality, transformed into a z-score, were generated: betweenness, closeness, and strength. Data were compared (t-test) and effect sizes were identified with Hedges' g. Large effect sizes were observed for swimming performance improvements in BREAST (32.0 ± 7.5 to 24.5 ± 3.8 s; g = 1.26; Δ = −21.9 %) and FLY (30.3 ± 7.0 to 21.8 ± 3.6 s; g = 1.52; Δ = −26.5 %). Small to moderate effect sizes were observed for anthropometric changes. Moderate effect size was observed for maturity offset changes (−2.0 ± 0.9 to −1.3 ± 1.0; g = 0.73; Δ = 50.9 ± 281 %). Changes in maturity offset, stroke rate (SR), and stroke length for both BREAST and FLY swimming speeds were highlighted by the weight matrix. For betweenness, closeness, and strength, changes in arm span (AS) (BREAST) and stroke length (FLY) were remarkable. The dynamic process of athletic development and the perception of complexity of fluctuations and associations between performance-related variables were underpinned, particularly for simultaneous swimming techniques in age-group swimmers.

Resumo Considerando a importância da diversidade de experiências motoras aquáticas para a melhor relação do indivíduo com o ambiente, o presente estudo teve como objetivo analisar as atividades realizadas na iniciação de crianças à natação. Ao longo deste estudo foram identificadas e analisadas as atividades propostas por professores em 36 aulas observadas de modo sistemático. Dentre os resultados, das 36 aulas, de oito professores, 33 continham atividades de técnica de nado, em um total de 86 exercícios somados e realizados 134 vezes. Conclui-se que há a necessidade de se repensar a pedagogia da natação, pois a predominância no cenário atual é o ensino técnico dos quatro estilos competitivos, antes mesmo do indivíduo se tornar independente e demonstrar competência no meio aquático.

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Aims: analyze kinematics, anthropometrics, and maturation during a training season in 12 y and underagegroup swimmers, quantifying changes and estimating their contributions to the 200-m maximal front crawl time trial test (T200) (time trial/fixed distance), as an event representative of the swimming performance. Methods: Nineteen age-group swimmers (11 girls and 8 boys; age 10.0 ± 1.3 y and 10.6 ± 1.0 y) performed a T200 four times during the training season. Changes in kinematic and anthropometric variables throughout the season were calculated. We applied generalized estimating equations to compare the variables over the four experimental tests. Multiple linear regressions were applied to identify the most influential variables and the relative contribution of anthropometrics and kinematics to swimming performance of T200 at baseline (pre-season) and after (using delta values) each macrocycle. Results:Large improvements (d = 1.76) were observed in the T200's performance (from 85.5 ± 38.2 at pre-season to 175.2 ± 50.1 FINA points at the end season). A gender effect was not identified. Stroke rate, stroke length, and stroke index explained, respectively 59, 23, and 17% of the T200 performance changes along the season (R 2 = 0.81; F = 26.9; p < 0.001; Durbin-Watson: 1.5). Anthropometric was not related to performance changes, with kinematic being the most determinant factor. Conclusion: Kinematical approaches must be carefully considered by coaches when planning 12 y and underage-group swimmers training programs.

Abstract Objective: to verify if three-weeks of training cessation affects 200 m front crawl performance and kinematics in 12 years old and under age-group swimmers controlling for anthropometric changes. Method: Sixteen age-group swimmers (11 girls and 5 boys, age: 10.2 ± 1.2 y) performed a 200 m front crawl test (T200) (time trial) PRE- and POST three-weeks (off-season), where performance, kinematics and anthropometrics variables were obtained. Results: Height increased ~1.0 cm (CI: 0.70 to 1.3 cm; p < 0.001; d = 0.07). Trivial changes were observed for performance (mean diff: 3.3 s CI: -6.7 to 13.9; p = 0.69; d = 0.08) and kinematical variables (p from 0.69 to 0.84; d < 0.001 for all). High intraclass correlations (ICC: 0.69 to 0.84; p < 0.001) were observed for all variables after three-weeks, indicating stability over time. Conclusion: Three-weeks off-season does not impair swimming T200 performance and kinematic variables in 12 years old and under age-group swimmers. Keywords: swimming, detraining, performance, kinematics, anthropometrics