Browsing by Author "Marinho, D.A."
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- 100m and 200m front crawl performance prediction based on anthropometric and physiological measurementsPublication . Reis, Victor M.; Silva, A.J.; Carneiro, André Luiz; Marinho, D.A.; Novaes, Giovanni Silva; Barbosa, Tiago M.The identification of the variables that are able to predict swimming performance is one of the main purposes of the “swimming science” community. Research question: The aims of the study were: (i) to compare the anthropometric and physiological profiles of 100m and 200m front crawl swimmers and; (ii) to identify anthropometric and physiological variables that account for the prediction of the swimming performance at the 100m and 200m front crawl events. Methods: Twenty-six male swimmers were divided in two groups (12 for 100m group and 14 to 200m group). The swimmers’ personal best performance for the 100m and the 200m front crawl was converted to FINA points. The subjects performed a graded swimming test and an all-out test (100 or 200m maximal swims) in different days, in which physiological measures were evaluated. Forward step-by-step linear regression models were computed to predict swimming performance. The subjects’ performances (season best and all-out test) were taken as dependent variables. The age, physiological and anthropometric measures were selected as independent variables. Results: Anthropometric and physiological profiles of 100 and 200m swimmers are different and the mean oxygen uptake during exercise combined with training experience may explain 200m front crawl best season performance with a high precision (≈2% error). The models computed were able to predict from 44 % (i.e. 200m all-out bout) to 61 % (i.e. 200m season best) swimming performance. Predictive power of the models was less accurate in the 100m event (error > 10%). Conclusions: The authors conclude that the extent to which the physiological and anthropometric variables combine to predict performance probable is group-specific.
- 13th FINA World Championship finals: stroke kinematical and race times according to performance, gender and eventPublication . Jesus, Sérgio; Costa, M.J.; Marinho, D.A.; Garrido, Nuno D.; Silva, A.J.; Barbosa, Tiago M.The aim of this work was to compare the stroke kinematics and race times of the freestyle final races at the 13th FINA World Championships between: (i) the three medalists versus the last three finalists; (ii) males versus female swimmers; (iii) all events in each gender. Data was collected from the champioships official web site. There were no significant differences in the stroke kinematics neither in the race times between medallists and non-medallists. There were significant effects in the stroke kinematics and race times according to race event. There were significant effects in the stroke kinematics and race times according to swimmers gender. It seems there are different tactics and biomechanical strategies according to gender and swimming event.
- 13th FINA World Championship finals: stroke kinematical and race times according to performance, gender and eventPublication . Jesus, Sérgio; Costa, M.J.; Marinho, D.A.; Garrido, Nuno D.; Silva, A.J.; Barbosa, Tiago M.The aim of this work was to compare the stroke kinematics and race times of the freestyle final races at the 13th FINA World Championships between: (i) the three medalists versus the last three finalists; (ii) males versus female swimmers; (iii) all events in each gender. Data was collected from the champioships official web site. There were no significant differences in the stroke kinematics neither in the race times between medallists and non-medallists. There were significant effects in the stroke kinematics and race times according to race event. There were significant effects in the stroke kinematics and race times according to swimmers gender. It seems there are different tactics and biomechanical strategies according to gender and swimming event.
- 13th FINA World Championship finals: stroke kinematical and race times according to performance, gender and eventPublication . Jesus, Sérgio; Costa, M.J.; Marinho, D.A.; Garrido, Nuno D.; Silva, A.J.; Barbosa, Tiago M.
- 13th FINA world Championship: analysis of swimsuits used by elite male swimmersPublication . Neiva, Henrique P.; Vilas-Boas, João Paulo; Barbosa, Tiago M.; Silva, A.J.; Marinho, D.A.The polyurethane swimsuits has become the notice around the pools in the past couple years. A better body position and the reducing of drag are believed to be some of the reasons that allow the swimmers wearing these swimsuits to go faster (Kainuma et al., 2009). The purpose of this study was to verify the distribution of different swimsuits used by male swimmers during the finals at the last world championships being held at Rome in 2009
- A adaptação ao meio aquático com recurso a situações lúdicasPublication . Barbosa, Tiago M.; Costa, M.J.; Marinho, D.A.; Silva, A.J.; Queirós, Telma Maria GonçalvesUm programa introdutório às actividades aquáticas implica um processo de familiarização e adaptação com o meio aquático. Estes programas introdutórios têm uma forte adesão por parte de alunos na faixa dos três até meados dos seis ou sete anos de idade. Durante décadas os modelos de ensino-aprendizagem da adaptação ao meio aquático propostos caracterizavamse por estilos de ensino mais rígidos e formais. Hoje em dia, os estilos de ensino na adaptação ao meio aquático acompanham a tendência de outras actividades aquáticas e inclusive paradigmas de ensino alicerçados na componente lúdica e no jogo. Um estilo de ensino mais lúdico fundamenta-se na proposta de uma tarefa com um determinado objectivo onde podem existir múltiplas soluções correctas. Ora dada a faixa etária a que se destinam a maioria dos programas de adaptação ao meio aquático, este estilo de ensino menos formatado, que dê uma maior liberdade criativa ao aluno será uma mais-valia. Foi objectivo deste trabalho propor uma selecção de jogos aquáticos de índole educativa para serem apresentados num programa de adaptação ao meio aquático com crianças e jovens.
- Aerobic training response in young swimmers of different levelPublication . Marinho, D.A.; Garrido, Nuno D.; Barbosa, Tiago M.; Neiva, Henrique P.; Costa, Aldo M.; Silva, A.J.; Marques, Mário C.Some authors (e.g. Maclaren and Coulson, 1999; Dekerle, 2006) reported that aerobic training has a positive effect on critical velocity in swimming. However, it raises the question whereas this effect is similar among swimmers of different performance level. Therefore, the purpose of this study was to determine the training responses in aerobic parameters (critical velocity and critical stroke rate) in young swimmers of different level during an in-season period of training.
- Aerodynamic analysis of human walking, running and sprinting by numerical simulationsPublication . Forte, Pedro; Sousa, Nuno; Teixeira, José Eduardo; Marinho, D.A.; Monteiro, A.M.; Bragada, José A.; Morais, J.E.; Barbosa, Tiago M.The drag in walking, running, and sprinting locomotion can be assessed by analytical procedures and experimental techniques. However, assessing the drag variations by these three main locomotion’s (i.e., walking, running, and sprinting) were not found using computational fluid dynamics. (CFD). Thus, the aim of this study was two-fold: (1) to assess the aerodynamics of human walking, running, and sprinting by CFD technique; 2) compare such aerodynamic characteristics between walking and running. Three 3D models were produced depicting the walking, running, and sprinting locomotion techniques, converted to computer aided design models and meshed. The drag varied with 4 locomotion type. Walking had the lowest drag, followed-up by running and then sprinting. At the same velocities, the drag was larger in walking than in running and increased with velocity. In conclusion, drag varied with locomotion type. Walking had the lowest drag, followed-up by running and then sprinting. At the same velocities, the drag was larger in walking than in running and increased with velocity.
- Aerodynamics of a wheelchair sprinter racing at the 100m world record pace by CFDPublication . Forte, Pedro; Marinho, D.A.; Morais, J.E.; Morouço, Pedro; Pascoal-Faria, Paula; Barbosa, Tiago M.The aim of this study was to analyze aerodynamics in a racing position of a wheelchair-racing sprinter, at the world record speed. The athlete and wheelchair were scanned at the beginning of the propulsive phase position (hands near the handrims at 12h) for the 3D model acquisition. Numerical simulation was run on Fluent, having as output the pressure, viscosity and total drag force, and respective coefficients of drag at the world record speed in T-52 category. Total drag was 7.56N and coefficient of drag was 1.65. This work helped on getting a deeper insight about the aerodynamic profile of a wheelchair-racing athlete, at a 100m world record speed.
- Agreement between different methods to measure the active drag coefficient in front-crawl swimmingPublication . Morais, J.E.; Barbosa, Tiago M.; Garrido, Nuno D.; Cirilo-Sousa, Maria S.; Silva, A.J.; Marinho, D.A.The aim of this study was to analyze the agreement of the active drag coefficient measured through drag and propulsion methods. The sample was composed of 18 swimmers (nine boys: 15.9 ± 0.9 years; nine girls: 15.3 ± 1.2 years) recruited from a national swimming team. The velocity perturbation method was used as the drag measurement system and the Aquanex system as the propulsion system. For both sexes combined, the frontal surface area was 0.1128 ± 0.016 m2, swim velocity 1.54 ± 0.13 m∙s-1, active drag 62.81 ± 11.37 N, propulsion 68.81 ± 12.41 N. The level of the active drag coefficient agreement was calculated based on the mean values comparison, simple linear regression, and Bland Altman plots. The mean data comparison revealed non-significant differences (p > 0.05) between methods to measure the active drag coefficient. Both the linear regression (R2 = 0.82, p < 0.001) and Bland Altman plots revealed a very high agreement. The active drag coefficient should be the main outcome used in the interpretation of the swimmers’ hydrodynamic profile, because it is less sensitive to swimming velocity. Coaches and researchers should be aware that the active drag coefficient can also be calculated based on propulsion methods and not just based on drag methods. Thus, the swimming community can now use different equipment to measure the hydrodynamics of their swimmers