The role of the biomechanics analyst in swimming training and competition analysis.

Swimming analysts aid coaches and athletes in the decision-making by providing evidence-based recommendations. The aim of this narrative review was to report the best practices of swimming analysts that have been supporting high-performance athletes. It also aims to share how swimming analysts can translate applied research into practice. The role of the swimming analyst, as part of a holistic team supporting high-performance athletes, has been expanding and is needed to be distinguished from the job scope of a swimming researcher. As testing can be time-consuming, analysts must decide what to test and when to conduct the evaluation sessions. Swimming analysts engage in the modelling and forecast of the performance, that in short- and mid-term can help set races target-times, and in the long-term provide insights on talent and career development. Races can be analysed by manual, semi-automatic or fully automatic video analysis with single or multi-cameras set-ups. The qualitative and quantitative analyses of the swim strokes, start, turns, and finish are also part of the analyst job scope and associated with race performance goals. Land-based training is another task that can be assigned to analysts and aims to enhance the performance, prevent musculoskeletal injuries and monitor its risk factors.

How do swimmers pace the 400 m freestyle and what affects the pacing pattern?

To describe the pacing pattern of elite 400 m freestyle swimmers, understand how athletes select the first half compared to their 200-m race pace, and correlate critical speed (CS) and D' with pacing parameters. The best all-time 400 m performances were obtained, and 200 m performances were retrieved from the same competition. Twenty-four performances were selected and, when possible, 50 m-splits were obtained. CS and D' were calculated based on the 200 m and 400 m performances. Most athletes adopted a parabolic pacing pattern. Performance in the 400 m correlated with that of the 200 m (rho = 0.418, p = 0.042), the % difference between 200 m performance and 200 m split correlated with CS (rho = -0.595, p = 0.002) and with D' (rho = 0.808, p < 0.001). The correlation between D' and % difference between average speed and CS was nearly perfect (rho = 1.000, p < 0.001). Recommendations of having the first half of the 400 m 4-5 s slower than their 200 m race do not seem to be appropriate for all swimmers and depends on physiological abilities.

Anthropometric parameters of cadets among different military sports / Parámetros antropométricos de cadetes entre los diferentes deportes militares

This study compared anthropometric parameters among different military sports. One hundred and seventy male cadets of the Brazilian Air Force Academy, who were participants of athletics (n= 33, 20.5±1.3 years), basketball (n= 11, 19.9±1.8 years), fencing (n= 10, 19.9±0.7 years), soccer (n= 21, 20.9±1.6 years), judo (n= 17, 20.7±1.0 years), swimming (n= 15, 20.4±1.2 years), orienteering (n= 10, 21.3±1.6 years), military pentathlon (n= 11, 20.7±1.2 years), water polo (n=10, 21.1±0.9 years), shooting (n= 18, 21.3±1.2 years) or volleyball (n= 14, 20.9±1.7 years) military competitive teams, participated in this study. Height, body mass, body mass index, fat percentage, lean body mass, fat mass, waist and hip perimeters, and waist-hip ratio were measured. Main effects were detected for height, body mass, body mass index, lean body mass, waist and hip perimeters. The only significant finding was that orienteers present lower lean body mass than volleyball and water polo players. These results point out the homogeneity of group anthropometric parameters (except lean body mass), suggesting that military coaches do not rely on the anthropometric parameters, but on specific skills demonstrated during initial period of practice to choose athletes for their teams.

Este estudio comparó los parámetros antropométricos entre cadetes que practican diferentes deportes militares. Ciento setenta cadetes hombres de la Academia de la Fuerza Aérea, que eran participantes de equipos militares competitivos de atletismo (n= 33, 20,5±1,3 años), baloncesto (n= 11, 19,9±1,8 años), esgrima (n= 10, 19,9±0,7 años), fútbol (n=21, 20,9±1,6 años), judo (n= 17, 20,7±1,0 años), natación (n= 15, 20,4±1,2 años), orientación (n= 10, 21,3±1,6 años), pentatlón militar (n= 11, 20,7±1,2 años), polo acuático (n= 10, 21,1±0,9 años), tiro (n= 18, 21,3±1,2 años) y voleibol (n= 14, 20,9±1,7 años) participaron en este estudio. Se midió la altura, masa corporal, índice de masa corporal, porcentaje de grasa corporal, masa magra, masa grasa, perímetros de cintura y cadera, y la relación cintura-cadera. No se detectaron variaciones de altura, masa corporal, índice de masa corporal, masa magra corporal, perímetro de cintura y cadera. El único hallazgo significativo fue que los orientadores tenían una masa corporal magra más baja que los jugadores de voléibol y polo acuático. Estos resultados apuntan a la homogeneidad de los parámetros antropométricos en grupos (excepto la masa magra), lo que sugiere que los instructores militares no dependen de los parámetros antropométricos, sino de las habilidades específicas demostradas durante el período de la práctica inicial en la selección de los atletas para sus equipos.

Effect of hand paddles and parachute on butterfly coordination.

This study investigated the effects of hand paddles, parachute and hand paddles plus parachute on the inter-limb coordination of butterfly swimming. Thirteen male swimmers were evaluated in four random maximal intensity conditions: without equipment, with hand paddles, with parachute and with hand paddles + parachute. Arm and leg stroke phases were identified by 2D video analysis to calculate the total time gap (T1: time between hands' entry in the water and high break-even point of the first undulation; T2: time between the beginning of the hand's backward movement and low break-even point of the first undulation; T3: time between the hand's arrival in a vertical plane to the shoulders and high break-even point of the second undulation; T4: time between the hand's release from the water and low break-even point of the second undulation). The swimming velocity was reduced and T1, T2 and T3 increased in parachute and hand paddles + parachute. No changes were observed in T4. Total time gap decreased in parachute and hand paddles + parachute. It is concluded that hand paddles do not influence the arm-to-leg coordination in butterfly, while parachute and hand paddles + parachute do change it, providing a greater propulsive continuity.

The use of hand paddles and fins in front crawl: biomechanical and physiological responses / Utilização de palmares e nadadeiras no nado crawl: respostas biomecânicas e fisiológicas

Paddles and fins are used during swim training and practice as tools for improving performance. The use of these equipment can alter physiological and kinematic parameters of swimming. The purpose of this literature review was to present and discuss the effects of paddles and fins on kinematic and physiological variables in front crawl, and provide update on the topic for teachers, researchers, coaches and swimmers. Thirty articles were reviewed. To crawl, paddles can change the averages of stroke length and stroke rate, the average swimming speed, the absolute duration of the stroke phases and the index of coordination. Fins can modify the average stroke rate, the average swimming speed, the kick frequency and deep, and the energy cost. We found no studies that verified the longitudinal effects of the use of paddles and fins on these parameters.

Palmares e nadadeiras são utilizados durante a prática e o treinamento da natação como ferramentas para a melhora do desempenho. A utilização desses equipamentos pode alterar parâmetros cinemáticos e fisiológicos do nado. Os objetivos dessa revisão de literatura foram apresentar e discutir os efeitos dos palmares e nadadeiras sobre variáveis cinemáticas e fisiológicas no nado crawl e fornecer atualização sobre o tema a professores, pesquisadores, treinadores e nadadores. Trinta artigos foram revisados. Para o nado crawl, palmares podem alterar o comprimento e a frequência média de braçadas, velocidade média de nado, duração absoluta das fases da braçada e índice de coordenação. Nadadeiras podem modificar a frequência média de braçadas, velocidade média de nado, frequência de pernada e profundidade da pernada e custo energético. Não foram encontrados estudos que verificaram os efeitos longitudinais da utilização de nadadeiras e palmares nesses parâmetros.

Acute responses of biomechanical parameters to different sizes of hand paddles in front-crawl stroke.

This study investigated the acute effects of different sizes of paddles on the force-time curve during tethered swimming and swimming velocity in front-crawl stroke. Fourteen male swimmers (20.0 ± 3.7 years; 100-m best time: 53.70 ± 0.87 s) performed two 10-s maximal efforts in tethered swimming to obtain peak force, average force, impulse, rate of force development, stroke duration and time to peak force. Swimming velocity, stroke rate and stroke length were obtained from two 25-m maximal swims. Both tests were repeated in five conditions: free swimming, wearing small (280 cm (2) ), medium (352 cm (2) ), large (462 cm (2) ) and extra-large (552 cm (2) ) hand paddles. Compared to free swimming, paddles provided significant increases of peak force (medium: 11.5%, large: 16.7%, extra-large: 21.7%), impulse (medium: 15.2%, large: 22.4%, extra-large: 30.9%), average force (medium: 5.1%, large: 7.5%), rate of force development (extra-large: 11.3%), stroke duration (medium: 9.3%, large: 11.8%, extra-large: 18.5%), time to peak force (medium: 11.1%, large: 15.9%, extra-large: 22.1%), swimming velocity (medium: 2.2%, large: 3.2%, extra-large: 3.7%) and stroke length (medium: 9.0%, large: 9.0%, extra-large: 14.8%), while stroke rate decreased (medium: -6.2%, large: -5.5%, extra-large: -9.5%). It is concluded that medium, large and extra-large paddles influence the force-time curve and change swimming velocity, suggesting these sizes may be useful for force development in water.

Reprodutibilidade da curva força-tempo do estilo "Crawl" em protocolo de curta duração / Reliability of front-Crawl's force-time curve in a short duration protocol

O objetivo deste estudo foi analisar a reprodutibilidade dos parâmetros biomecânicos da curva força-tempo do estilo "Crawl" em um protocolo de 10 s no nado atado. Dezesseis nadadores do sexo masculino (idade: 20,4 ± 4,0 anos; tempo na prova de 100 m livre: 53,68 ± 0,99 s) realizaram dois esforços máximos de 10 s no nado atado. Os parâmetros força pico, força média, taxa de desenvolvimento de força, impulso, duração da braçada, tempo para atingir a força pico e força mínima foram representados pela média de oito braçadas consecutivas obtidas em cada tentativa. Utilizou-se o teste t para observar as diferenças entre os esforços para cada parâmetro. O nível de significância estabelecido foi de 5%. A reprodutibilidade relativa foi medida pelo coeficiente de correlação de Pearson e a consistência entre as duas tentativas pelo coeficiente de correlação intraclasse (CCI). A reprodutibilidade absoluta foi verificada pelo coeficiente de variação (CV). Não foi demonstrada diferença estatisticamente significante para nenhum parâmetro biomecânico quando comparados os dois esforços. Os elevados CCI e baixos CV indicaram alta consistência interna dos parâmetros analisados. Conclui-se que os parâmetros biomecânicos analisados a partir do nado atado são reprodutíveis quando empregado protocolo de curta duração o que demonstra a possibilidade de utilização do protocolo com alto grau de confiabilidade, por parte de treinadores e atletas.

The aim of the present study was to analyze the reliability of biomechanical parameters of the front-Crawl's force-time curve in a 10-s protocol. Sixteen national competitive male swimmers (20.4 ± 4.0 years; 100-m best time: 53.68 ± 0.99 s) performed two 10-s maximal efforts in tethered swimming. Peak force, average force, impulse, rate of force development, stroke duration, time to peak force and minimum force were represented by the mean of eight consecutive strokes obtained in each trial. The paired student-t test was used to verify differences between trials for each biomechanical parameter. The significance level adopted was 5%. Relative reliability was tested by Pearson correlation coefficient and the consistency between trials by means of intraclass coefficient (CCI). The coefficient of variation was used to verify the absolute reliability. No significant differences between the trials to any biomechanical parameter were found. High CCI values and low CV values revealed the high internal consistency of the analyzed variables. It can be concluded that the biomechanical parameters regarding the tethered swimming are reliable in short duration protocols and may be used by coaches and athletes for monitoring training.

Efeito do treinamento de força na relação força muscular desempenho aeróbio de nadadores competitivos / Effect of strength training on muscular strength-aerobic performance relationship for competitive swimmers

O objetivo deste estudo foi verificar os efeitos do treinamento de força na relação força muscular fora da águadesempenho aeróbio dentro da água. Dezesseis nadadores foram divididos em grupos controle (GC) e experimental (GE), e submetidos a dezessete semanas de treinamento dentro da água. O GE também realizou um treinamento de força fora daágua (TFFA), objetivando o ganho de potência. Antes e após as doze semanas do TFFA foi aplicado o teste de 10 minutos (T10) para avaliar a resistência aeróbia, 1 ação voluntária máxima (1AVM) e repetições máximas em 30s (REM) com 70% da carga de 1AVM, de onde foi calculada a quilagem total. Valores obtidos em 1AVM e quilagem foram relativizados pela massa corporal. Não foi observada correlação signifi cante entre as alterações percentuais do T10 e dos indicadores de força muscular fora da água, apesar do aumento significante deles no GE. Conclui-se que o TFFA não gera melhora no Desempenho aeróbio dentro da água...

The aim of this study was to verify the effects of strength training on the muscular strength-aerobic performancerelationship. Sixteen swimmers were assigned to control (CG) or experimental (EG) groups and underwent seventeen weeks of swimming training. Swimmers in the EG also performed dry land strength training (DLST), lasting twelve weeks,and aiming to develop power. A 10 minutes test (T10) was taken before and after the 12 weeks of DLST, in order to evaluate aerobic resistance, one maximum voluntary contraction (1MVC) and maximum repetition in 30s (REM) using 70% of 1MVC, where total weight was calculated. Total weight, T10, and 1MVC were all normalized for body mass. There was no signifi cantcorrelation between percent changes in T10 and dry land muscle strength, despite signifi cant increases being detected in dry land muscle strength. It can be concluded that nonspecifi c training does not improve aerobic performance in swimming...

Efeito do treinamento de força no desempenho da natação / Effects of strength training on swimming performance

O objetivo deste trabalho foi verificar se a utilização do treinamento de força fora da água influenciou o desempenho de nadadores. Dezesseis nadadores (21,93 anos mais ou menos 2,17) foram aleatoriamente dividido sem grupos Controle (GC / n = 8) e Experimental (GE / n = 8), realizando o mesmo tipo de treinamento. GE também foi submetido ao treinamento de força objetivando o ganho de potência. As avaliações ocorreram na terceira (Pré) e na décima sétima (Pós) semana. Dentro da água a velocidade média foi coletada nas distâncias de 25 (T25) e 50 m (T50). Fora da água foram utilizados os testes de uma repetição máxima (1RM) e repetições máximas com 70% de 1RM (RSM) no período de 30 segundos para supino reto fechado (SRF), remada alta (RA) e leg press inclinado (LPI). Alterações Pré e Pós foram detectadas pela análise de variância por medidas repetidas (ANOVA) seguidas pelo post-hoc de Scheffé (p < 0,05). T25 apresentou diferenças significantes de Pré para Pós em ambos os grupos (5,21% para o GC e 3,74% para o GE). Para T50 também houve diferenças de Pré para Pós para ambos os grupos(5,69% e 5,33% para GC e GE, respectivamente). No teste de 1RM, o GE apresentou melhoras (p < 0,05) de 16,47% no SRF, 17,34% na RA e 25,31%. Já o GC apresentou alteração significante apenas no LPI (14,01%). RSM não apresentou alterações significantes em nenhum dos grupos. Apesar do aumento da força avaliada fora da água no GE, o desempenho foi melhor no GC. Conclui-se que, a metodologia aplicada ao treinamento de força não influenciou positivamente o desempenho dentro da água.