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- Is there any effect of symmetry on velocity of the four swimming strokes?Publication . Bartolomeu, Raúl Filipe; Rodrigues, Pedro M.; Santos, Catarina C.; Costa, M.J.; Barbosa, Tiago M.The different characteristics of the four swimming strokes affect the interplay between the four limbs, acting as a constraint to the force produced by each hand and foot. The purpose of this study was to analyze the symmetry of force production with a varying number of limbs in action and see its effect on velocity. Fifteen male swimmers performed four all-out bouts of 25-m swims in the four strokes in full-body stroke and segmental actions. A differential pressure system was used to measure the hands/feet propulsive force and a mechanical velocity meter was used to measure swimming velocity. Symmetry index was calculated based on the force values. All strokes and conditions presented contralateral limb asymmetries (ranging from 6.73% to 28% for the peak force and from 9.3% to 35.7% for the mean force). Backstroke was the most asymmetric stroke, followed-up by butterfly, front crawl, and breaststroke. Kicking conditions elicited the higher asymmetries compared with arm-pull conditions. No significant associations were found between asymmetries and velocity. The absence of such association suggests that, to a certain and unknown extent, swimming may benefit from contralateral limb asymmetry
- 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.
- 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).