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- Comparison of the anthropometrics, kinematics and kinetics in young swimmers of different competitive levelsPublication . Barbosa, Tiago M.; Bartolomeu, Raúl Filipe; Morais, J.E.; Costa, M.J.The biomechanics plays a major role in the performance delivered by young swimmers. However, the literature addresses mostly the differences in the kinematics across young swimmers of different competetive levels, being scarce on the kinetics. The aim was to compare the anthrpmetics, kinematics and kinetics in young swimmers of different competetive levels.
- Validation of StepTest4all for assessing cardiovascular capacity in young adultsPublication . Bragada, José A.; Bartolomeu, Raúl Filipe; Rodrigues, Pedro M.; Magalhães, Pedro; Bragada, João P.; Morais, J.E.Background: Cardiovascular capacity, expressed as maximal oxygen uptake (VO2max), is a strong predictor of health and fitness and is considered a key measure of physiological function in the healthy adult population. The purpose of this study was to validate a specific step test (StepTest4all) as an adequate procedure to estimate cardiovascular capacity in young adults. Methods: The sample was composed of 56 participants, including 19 women (aged 21.05 2.39 years, body mass = 57.50 6.64 kg, height = 1.62 0.05 m, body mass index = 22.00 2.92 kg/m2) and 37 men (aged 22.05 3.14 years, body mass = 72.50 7.73 kg, height = 1.76 0.07 m, body mass index = 23.34 2.17 kg/m2). Participants were included in one of the following groups: (i) the group used to predict the VO2max, and (ii) the group used to validate the prediction model. All participants performed the StepTest4all protocol. The step height and the intensity of the effort was determined individually. Heart rate and oxygen uptake were measured continuously during rest, effort, and recovery phases. The validation process included the following three stages: (i) mean data comparison, (ii) simple linear regression, and (iii) Bland–Altman analysis. Results: The linear regression retained, as significant predictors of the VO2max, sex (p < 0.001) and heart rate recovery for one minute (p = 0.003). The prediction equation revealed a high relationship between measurements (R2 = 63.0%, SEE = 5.58). The validation procedure revealed non-significant differences (p > 0.05) between the measured and estimated maximal oxygen uptake, high relationship (R2 = 63.3%), and high agreement with Bland–Altman plots. Thus, VO2max can be estimated with the formula: VO2max = 22 + 0.3 (HRR1min) + 12 (sex), where HRR1min is the magnitude of the HR decrease (bpm) in one minute immediately after the step was stopped, and sex: men = 1, women = 0. Conclusions: The StepTest4all is an adequate procedure to estimate cardiovascular capacity, expressed as VO2max, in young adults. In addition, it is possible to determine the qualitative level of cardiovascular capacity from the heart rate recovery for one minute, more specifically, poor: <20, moderate: 20 to 34, good: 35 to 49, and excellent: 50. This procedure has the benefit of being simple to apply and can be used by everyone, even at home, without specialist supervision.
- Understanding the importance of drag coefficient assessment for a deeper insight into the hydrodynamic profile of swimmersPublication . Morais, J.E.; Marinho, D.A.; Bartolomeu, Raúl Filipe; Barbosa, Tiago M.The main objective of this study was to confirm that the passive drag coefficient is less dependent on swimming speed than the passive drag, Froude, and Reynolds numbers, even as swimming speed increases. The sample consisted of 12 young proficient non-competitive swimmers (seven males and five females: 20.4 ± 1.9 years). Passive drag was measured with a low-voltage isokinetic engine at 1.2, 1.4, 1.6 and 1.8 m/s. The frontal surface area was measured using digital photogrammetry. Passive drag showed significant differences with a strong effect size over the four towing speeds measured (F = 116.84, p < 0.001, η2 = 0.91) with a quadratic relationship with speed. The Froude and Reynolds numbers had similar trends, but with linear relationships. Conversely, the passive drag coefficient showed non-significant differences across the four towing speeds (F = 3.50, p = 0.062, η2 = 0.33). This strongly suggests that the passive drag coefficient should be the variable of choice for monitoring the hydrodynamic profile of swimmers rather than the absolute value of passive drag.
- Avaliação das assimetrias propulsivas em nado livre: ferramenta e diagnóstico para o processo de treinoPublication . Bartolomeu, Raúl Filipe; Rodrigues, Pedro M.; Morais, J.E.; Marinho, D.A.; Costa, M.J.; Barbosa, Tiago M.Atualmente já é possível adquirir no mercado sensores de pressão que se colocam nas mãos e/ou pés de onde se derivam as forças propulsivas com a possibilidade de se detetarem possíveis assimetrias. Foi objetivo do presente estudo ter uma compreensão clara de tais assimetrias num ambiente ecologicamente válido (p.e., nado dinâmico em vez de nado amarrado). máxima em três variantes do nado de crol: completo (C), só com membros superiores (MS) e só com membros inferiores (MI). A medição da força propulsiva em cada uma das condições foi efetuada com recurso a um sistema de monitorização (Aquanex System, DU2V, STR, EUA). Como variáveis definiram-se: o pico de força, a força média, o índice de assimetria (IS) como descrito por Robinson et al (1987), a velocidade média (v) e a frequência gestual (FG).
- The aging influence on cardiorespiratory, metabolic and energy expenditure adaptations in head-out aquatic exercises: differences between young and elderly womenPublication . Bartolomeu, Raúl Filipe; Barbosa, Tiago M.; Morais, J.E.; Lopes, Vitor P.; Bragada, José A.; Costa, M.J.The purpose of this study was to (1) to establish the relationship between acute physiological responses and musical cadence; and (2) compare physiologic responses between young and older women. Eighteen older (mean = 65.06 ± 5.77 years) and 19 young (mean = 22.16 ± 2.63 years) women underwent an intermittent and progressive protocol performing the head-out aquatic exercise "rocking horse. Results showed that older women demonstrated lower mean heart rate (HR), blood lactate concentration (bLa) and oxygen uptake (VO2) at rest. Hierarchical linear modelling showed that variations in the rating of perceived effort (RPE) and individual metabolic equivalent of task (MET) did not differ significantly by age group. However, during exercise, physiological responses of younger women were significantly different than for older women: in mean values, for each increased musical beat per minute (b/min), mean bLa was 0.003 mmol/l, VO2 0.024 ml/kg/min, and energy expenditure (EE) 0.0001 kcal/kg/min higher for younger women. This study shows that increases in musical cadence increased the cardiorespiratory, metabolic and energy expenditure responses. However, these responses during increasing intensity seemed to differ between young and older women, with lower values for the elderly group, when performing head-out aquatic exercises.
- Association between the upper quarter dynamic balance, anthropometrics, kinematics, and swimming speedPublication . Bartolomeu, Raúl Filipe; Sampaio, Tatiana; Oliveira, João P.; Barbosa, Tiago M.; Morais, J.E.Besides recurrently assessed water-based parameters, there are also some individual characteristics that affect swimming performance that are not water related. In the past few years, dynamic balance has been associated with land sports performance. Conversely, evidence on this topic in swimming is scarce. The purpose of this study was to assess the association between on-land dynamic balance and swimming performance. Sixteen young adults and recreational swimmers were recruited for the present study (8 males 20.8 2.0 years, and 8 females 20.1 1.9 years). A set of anthropometric features were measured. The upper quarter Y-balance test was selected as a dynamic balance outcome, and swimming speed as the swimming performance indicator. The results showed a moderate and positive correlation between dynamic balance and swimming performance (p < 0.05). Speed fluctuation was highly and negatively related to swimming speed (p < 0.001), i.e., swimmers who had higher scores in the dynamic balance were more likely to deliver better performances. This suggests that in recreational swimmers, the stability and mobility of the upper extremity had a greater influence on swimming performance. Therefore, swimming instructors are advised to include dynamic balance exercises in their land-based training sessions to improve their swimmers’ performance
- Net Heart Rate for Estimating Oxygen Consumption in Active AdultsPublication . Bragada, José A.; Magalhães, Pedro; São-Pedro, Eric; Bartolomeu, Raúl Filipe; Morais, J.E.The aim of this study was to verify the accuracy of predicting oxygen consumption (O-2) in predominantly aerobic activities based on net heart rate (netHR), sex, and body mass index (BMI) in active adults. NetHR is the value of the difference between the resting HR (HRrest) and the average HR value obtained during a given session or period of physical activity. These activities must be continuous, submaximal, and of a stabilized intensity. The magnitude of the netHR depends mainly on the intensity of the exercise. The HR is measured in beats per minute (bpm). A total of 156 participants, 52 women and 104 men, between the ages of 18 and 81, had their netHR and net oxygen intake (netVO(2)) assessed. There were 79 participants in group 1 (prediction sample) (52 males and 27 females). There were 77 people in group 2 (validation sample) (52 males and 25 females). The results of the multiple linear regression showed that netVO(2) (R-2 = 85.2%, SEE = 3.38) could be significantly predicted by sex (p < 0.001), netHR (p < 0.001), and BMI (p < 0.001). The Bland-Altman plots satisfied the agreement requirements, and the comparison of the measured and estimated netVO(2) revealed non-significant differences with a trivial effect size. We calculated the formula NetVO(2) (mL/(kgmin)) = 16 + 3.67 (sex) + 0.27 (netHR) - 0.57 (BMI) to predict netVO(2), where netVO(2) is the amount of oxygen uptake (mL/(kgmin)) above the resting value, netHR is the heart rate (beats per minute) above the resting value measured during exercise, sex is equal to zero for women and one for men, and BMI is the body mass index. In addition, based on the knowledge of VO2, it was possible to estimate the energy expenditure from a particular training session, and to determine or prescribe the exercise intensity in MET (metabolic equivalent of task).