Percorrer por autor "Garrido, Nuno D."
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- 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.
- 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.
- 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
- Análise dos parâmetros cinemáticos determinantes do desempenho na prova de 200 m nado livrePublication . Ferreira, Maria Inês; Silva, A.J.; Oliveira, Diogo R.; Garrido, Nuno D.; Barbosa, Tiago M.; Marinho, D.A.; Reis, Victor M.Os objetivos deste estudo foram: i) caracterizar o nado submáximo e máximo do ponto de vista cinemático; ii) verificar a influência das variáveis cinemáticas na prova máxima de 200 metros crawl. Nove nadadores de elite nacionais realizaram dois testes: um submáximo, descontínuo de intensidade progressiva; outro máximo, que consistiu em uma simulação de uma prova de 200 m crawl. Foram estudados os parâmetros cinemáticos gerais da mecânica da braçada, a duração de cada fase do ciclo gestual, a velocidade do centro de massa e a variação intracíclica da velocidade horizontal. Verificaram-se diferenças cinemáticas significativas da frequência gestual, velocidade de deslocamento do centro de massa, duração total do ciclo gestual, duração da ação subaquática propulsora e da velocidade do centro de massa na fase de recuperação entre os testes. Identificou-se associações significativas entre o teste máximo e algumas variáveis cinemáticas como a velocidade do centro de massa e índice de nado. Palavras-chave: nado crawl; cinemática; prova submáxima; prova máxima.
- Analysis of the determinant kinematical parameters for performance in the 200-m freestyle swimming eventPublication . Ferreira, Maria Inês; Silva, A.J.; Oliveira, Diogo R.; Garrido, Nuno D.; Barbosa, Tiago M.; Marinho, D.A.; Reis, Victor M.Os objetivos deste estudo foram: i) caracterizar o nado submáximo e máximo do ponto de vista cinemático; ii) verificar a influência das variáveis cinemáticas na prova máxima de 200 metros crawl. Nove nadadores de elite nacionais realizaram dois testes: um submáximo, descontínuo de intensidade progressiva; outro máximo, que consistiu em uma simulação de uma prova de 200 m crawl. Foram estudados os parâmetros cinemáticos gerais da mecânica da braçada, a duração de cada fase do ciclo gestual, a velocidade do centro de massa e a variação intracíclica da velocidade horizontal. Verificaram-se diferenças cinemáticas significativas da frequência gestual, velocidade de deslocamento do centro de massa, duração total do ciclo gestual, duração da ação subaquática propulsora e da velocidade do centro de massa na fase de recuperação entre os testes. Identificou-se associações significativas entre o teste máximo e algumas variáveis cinemáticas como a velocidade do centro de massa e índice de nado. The main aims of this study were i) to perform a kinematic characterization of sub and maximal swimming speed; ii) to investigate the associations between the kinematic profiles and the 200 m front crawl style. Nine national level male swimmers performed two speed tests: a submaximal discontinuous speed trial of progressive speed intensity, and a maximal one, simulating a 200 m front crawl style. The stroke general kinematic parameters, the phases duration of the stroke cycle, the velocity of the centre of mass and the intra cyclic variation of the horizontal velocity were herein studied. Significant kinematic differences in relation to stroke rate, horizontal velocity of the centre of mass, total cycle duration, absolute and relative duration of the propulsive sub aquatic action and the velocity of the centre of mass during the arms recovery were compared between the speed tests. Significant correlations between the performance in the maximal speed and some kinematic variables were observed.
- Are wearable heart rate measurements accurate to estimate aerobic energy cost during low-intensity resistance exercise?Publication . Reis, Victor M.; Vianna, Jeferson M.; Barbosa, Tiago M.; Garrido, Nuno D.; Alves, José Vilaça; Carneiro, André Luiz; Aidar, Felipe José; Novaes, JeffersonThe aim of the present study was to assess the accuracy of heart rate to estimate energy cost during eight resistance exercises performed at low intensities: half squat, 45° inclined leg press, leg extension, horizontal bench press, 45° inclined bench press, lat pull down, triceps extension and biceps curl. 56 males (27.5 ± 4.9 years, 1.78 ± 0.06 m height, 78.67 ± 10.7 kg body mass and 11.4 ± 4.1% estimated body fat) were randomly divided into four groups of 14 subjects each. Two exercises were randomly assigned to each group and subjects performed four bouts of 4-min constant-intensity at each assigned exercise: 12%, 16%, 20% and 24% 1-RM. Exercise and intensity order were random. Each subject performed no more than 2 bouts in the same testing session. A minimum recovery of 24h was kept between sessions. During testing VO2 was measured with Cosmed K4b2 and heart rate was measured with Polar V800 monitor. Energy cost was calculated from mean VO2 during the last 30-s of each bout by using the energy equivalent 1 ml O2 = 5 calorie. Linear regressions with heart rate as predictor and energy cost as dependent variable were build using mean data from all subjects. Robustness of the regression lines was given by the scatter around the regression line (Sy.x) and Bland-Altman plots confirmed the agreement between measured and estimated energy costs. Significance level was set at p≤0.05. The regressions between heart rate and energy cost in the eight exercises were significant (p<0.01) and robustness was: half squat (Sy.x = 0,48 kcal·min-1), 45° inclined leg press (Sy.x = 0,54 kcal·min-1), leg extension (Sy.x = 0,59 kcal·min-1), horizontal bench press (Sy.x = 0,47 kcal·min-1), 45° inclined bench press (Sy.x = 0,54 kcal·min-1), lat pull down (Sy.x = 0,28 kcal·min-1), triceps extension (Sy.x = 0,08 kcal·min-1) and biceps curl (Sy.x = 0,13 kcal·min-1). We conclude that during low-intensity resistance exercises it is possible to estimate aerobic energy cost by wearable heart rate monitors with errors below 10% in healthy young trained males.
- Artificial Intelligence in Sub-Elite Youth Football Players: Predicting Recovery Through Machine Learning Integration of Physical, Technical, Tactical and Maturational DataPublication . Afonso, Pedro Miguel Vaz; Forte, Pedro; Branquinho, Luís; Ferraz, Ricardo; Garrido, Nuno D.; Teixeira, José EduardoMonitoring training load and recovery is essential for performance optimization and injury prevention in youth football. However, predicting subjective recovery in preadolescent athletes remains challenging due to biological variability and the multidimensional nature of training responses. This exploratory study examined whether supervised machine learning (ML) models could predict Total Quality of Recovery (TQR) using integrated external load, internal load, anthropometric and maturational variables collected over one competitive microcycle. Forty male sub-elite U11 and U13 football players (age 10.3 +/- 0.7 years; height 1.43 +/- 0.08 m; body mass 38.6 +/- 6.2 kg; BMI 18.7 +/- 2.1 kg/m2) completed a microcycle comprising four training sessions (MD-4 to MD-1) and one official match (MD). A total of 158 performance-related variables were extracted, including external load (GPS-derived metrics), internal load (RPE and sRPE), heart rate indicators (U13 only), anthropometric and maturational measures, and tactical-cognitive indices (FUT-SAT). After preprocessing and aggregation at the player level, five supervised ML algorithms-K-Nearest Neighbors (KNN), Support Vector Machine (SVM), Decision Tree (DT), Random Forest (RF), and Gradient Boosting (GB)-were trained using a 70/30 train-test split and 5-fold cross-validation to classify TQR into Low, Moderate, and High categories. Tree-based models (DT, GB) demonstrated the highest predictive performance, whereas linear and distance-based approaches (SVM, KNN) showed lower discriminative ability. Anthropometric and maturational factors emerged as the most influential predictors of TQR, with external and internal load contributing modestly. Predictive accuracy was moderate, reflecting the developmental variability characteristics of this age group. Using combined physiological, mechanical, and maturational data, these ML-based monitoring systems can simulate subjective recovery in young football players, offering potential as decision-support tools in youth sub-elite football and encouraging a more holistic and individualized approach to training and recovery management.
- Biomechanics and energetics as determinant factors of competitive swimming performance: exploratory approaches to link selected variablesPublication . Barbosa, Tiago M.; Marinho, D.A.; Garrido, Nuno D.; Costa, M.J.; Silva, A.J.