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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
- Force production and symmetry in water fitness exercises: a gender comparisonPublication . Santos, Catarina C.; Costa, M.J.; Bartolomeu, Raúl Filipe; Barbosa, Tiago M.; Rama, Luís M.The aim of this study was to analyse and compare propulsive forces, relative force production and symmetry between genders during water fitness exercises. Eighteen participants (women, n= 9; age: 20.67± 0.87 years; body mass: 58.18± 4.97 kg; height: 159.19± 5.85 cm; and men, n= 9; age: 22.11± 1.76 years; body mass: 72.93± 7.00 kg; height: 170.83± 5.57 cm) underwent two incremental protocols performing horizontal adduction (HA) and the rocking horse (RHadd) exercises, from 105 to 150 bpm. Propulsive peak force of dominant (PFD) and non-dominant upper-limbs (PFND) was assessed by a differential pressure system. An isokinetic dynamometer was used to collect the dry-land isometric peak strength of the dominant upper-limb. Significant differences between genders were found for most of the music cadences in HA and RHadd. Men were able to produce higher propulsive force values for both upper-limbs during the overall incremental protocol, whereas women reached a higher relative force production. However, no significant differences were found between both genders at the same music cadence. Most actions were asymmetric in women, whereas men showed a symmetric pattern. The cadence of 135 bpm elicits a symmetric motion in both genders while exercising water fitness exercises.
- 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.
- VO2 kinetics and tethered strength influence the 200-m front crawl stroke kinematics and speed in young male swimmersPublication . Sokołowski, Kamil; Bartolomeu, Raúl Filipe; Barbosa, Tiago M.; Strzała, MarekThe aim of this research was to examine the relationship between the fast component of oxygen consumption developed in 1-min V_O2 and force indices both measured in tethered swimming test and to assess the influence of the gathered indices on speed and swimming kinematics in 200-m front crawl race. Methods: Forty-eight male swimmers (aged 13.5 ± 0.9 years old) participated in this study. Testing included 1) 1-min all-out front crawl tethered swimming while oxygen consumption (breath by breath) and tethered forces were measured, 2) 200-m front crawl race-like swimming featuring kinematic analysis, and 3) biological age (BA) examination. Results: During the 1-min all-out tethered swimming test, a linear increase in oxygen consumption was observed. There were moderate to high partial correlations between particular periods of seconds in the 1-min V_O2: 31–60, 41–60, and 51–60 and Fmax, Fave, and Iave of tethered swimming, while 41–60 and 51–60 V_O2 were moderately to highly interrelated with all the swimming speed indices and SI. The swimming speed indices significantly interplayed with SL, SI, Fmax, Fave, and Iave. Partial correlations were computed with BA control. Conclusion: The ability of reaching a high level of V_O2 fast is essential for a swimmer’s energy production at short- and middle-distance events. Reaching a high level of V_O2 significantly determines tethered strength and swimming kinematics. The level of V_O2 influences the maintenance of a proper pulling force and the stroke technique of front crawl swimming in young male swimmers.
- 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.
- Underwater and surface tethered swimming, lower limb strength, and somatic traits as the basic indices of young swimmers’ sprint performancePublication . Sokołowski, Kamil; Bartolomeu, Raúl Filipe; Krężałek, Piotr; Bragada, José A.; Pałka, Tomasz; Ambroży, Dorota; Strzała, MarekPurpose: The ability to swim fast underwater is believed to be connected to lower limb strength and some somatic traits. The main purpose of the study was to evaluate strength and speed parameters based on the relationship between the strength of underwater dolphin kicks and the countermovement jump test (CMJ) among adolescent swimmers. Methods: 48 adolescent male swimmers (13.47 +/- 0.84 years) were examined for muscle mass of arms (mm arms), trunk (mm trunk), and legs (mm legs), body height (BH), and biological age (BA). An underwater tethered dolphin kicking test was conducted in a pool; average force (5Fave) and impulse per single cycle (5Iave) in the 5-second period were measured. Force indices (20Fave - average force from 20 seconds and 20Iave - average impulse per single cycle from 20 seconds) were also measured in 20-second tethered front crawl swimming. During CMJ testing, general lower body muscle motor capabilities were evaluated by extracting the work (CMJw [J]) and height (CMJh [m]) of the jump. Results: The strongest correlations were observed between: (a) 5Fave and BH, mm arms and CMJw; (b) CMJw, mm arms, and 20Fave; (c) indices of swimming speed and 5Iave (BA control); (d) total swimming velocity and average tethered swimming force (BA control). Moderate partial correlations (BA control) were noted between speed indices of swimming race and CMJ. Conclusions: The underwater tethered dolphin kick test is a useful predictor test of 50-m front crawl performance in young male swimmers, with better specificity for swimmers than CMJ results themselves.
- 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