RESUMO

Literature diverges about the performance improvement after dry-land training. Thus, the objective of the present study was to compare the effect of two models of dry-land training. Twenty-nine swimmers were divided into three groups, combined strength and power training (PTG), only strength training (STG), and a control group (CG). Measurements were taken for six weeks, before dry-land exposure (M1), after four weeks of specific training with exposure to dry-land training by two groups (M2), and after two weeks of taper without exposure to dry-land training (M3). Strength in specific exercises, jumping tests, and 50, 100, and 200m freestyle performance were evaluated on M1 and M3, while hematological and strength parameters in tethered swimming were measured in M1, M2, and M3. PTG showed time-effect improvement for 200, 100, and 50m performance (p<0.014), CG for 200 and 100m (p<0.047), and STG only for 100m (p:0.01). No differences were found in Δ performance between groups. PTG showed improvement in the peak force of tethered swimming on M2 (p:0.019), followed by a decrease on M3 (p:0.003). PTG and STG also showed an increase in creatinine, lactate dehydrogenase (LDH), and creatine kinase (CK) after M2 (p<0.038). Finally, it was concluded that both dry-land training sessions could change hematological parameters and improve physical attributes on dry-land and tethered swimming tests without improving performance.

RESUMO

This study aimed to apply an incremental tethered swimming test (ITT) with workloads (WL) based on individual rates of front crawl mean tethered force (Fmean) for the identification of the upper boundary of heavy exercise (by means of respiratory compensation point, RCP), and therefore to describe oxygen uptake kinetics (VO2k) and time limit (tLim) responses to WL corresponding to peak oxygen uptake (WLVO2peak). Sixteen swimmers of both sexes (17.6 ± 3.8 years old, 175.8 ± 9.2 cm, and 68.5 ± 10.6 kg) performed the ITT until exhaustion, attached to a weight-bearing pulley-rope system for the measurements of gas exchange threshold (GET), RCP, and VO2peak. The WL was increased by 5% from 30 to 70% of Fmean at every minute, with Fmean being measured by a load cell attached to the swimmers during an all-out 30 s front crawl bout. The pulmonary gas exchange was sampled breath by breath, and the mathematical description of VO2k used a first-order exponential with time delay (TD) on the average of two rest-to-work transitions at WLVO2peak. The mean VO2peak approached 50.2 ± 6.2 mL·kg-1·min-1 and GET and RCP attained (respectively) 67.4 ± 7.3% and 87.4 ± 3.4% VO2peak. The average tLim was 329.5 ± 63.6 s for both sexes, and all swimmers attained VO2peak (100.4 ± 3.8%) when considering the primary response of VO2 (A1' = 91.8 ± 6.7%VO2peak) associated with the VO2 slow component (SC) of 10.7 ± 6.7% of end-exercise VO2, with time constants of 24.4 ± 9.8 s for A1' and 149.3 ± 29.1 s for SC. Negative correlations were observed for tLim to VO2peak, WLVO2peak, GET, RCP, and EEVO2 (r = -0.55, -0.59, -0.58, -0.53, and -0.50). Thus, the VO2k during tethered swimming at WLVO2peak reproduced the physiological responses corresponding to a severe domain. The findings also demonstrated that tLim was inversely related to aerobic conditioning indexes and to the ability to adjust oxidative metabolism to match target VO2 demand during exercise.

RESUMO

This study investigated the effects of a 4-week training with hand paddles (HPD) on front-crawl swimming performance (SP), clean swimming speed (SPEED), stroke rate (SR), stroke length (SL) and tethered force (TF). Twenty swimmers (10 men and 10 women) were paired according to performance and gender, and were randomly assigned to control (CON, 22.4 ± 2.3 years) or HPD (21.8 ± 1.9 years) groups. During 4 weeks both groups performed the same training, except for a sprint training set (3 times/week, 10 × 10 strokes all-out, 1-min rest) completed with (HPD = 320 cm2) and without (CON) paddles. Afterwards, both groups performed the same training over a 2-week taper period. SP, SPEED, SR, SL and TF were assessed before (PRE) and after the 4-week period (POST), after the first (T1) and second taper weeks (T2). Swimmers rated their perceived exertion for the sprint training set (RPETS) and the training session for determining internal training load (ITL). SP, SPEED, SR, SL and TF did not change from PRE to POST, T1 and T2. ITL and RPETS were not different between groups. Training 4 weeks with HPD does not affect swimming performance, so the use of HPD remains unsupported in such period.

Assuntos

RESUMO

Synchronised swimming involves a variety of sculling movements essential for body support and propulsion but its study is scarce. We aimed to biomechanically compare standard and contra-standard sculling techniques, and to observe the relationship between measures. Six synchronised swimmers performed two, 30 s maximal intensity, fully tethered standard and contra-standard sculling motions. Kinetic and kinematic data were obtained using a load-cell and underwater cameras, respectively. Force decreased along both techniques' bouts, but no differences in-between techniques were noted for any kinetic variables. Standard sculling presented a higher cycle rate and a lower elbow mean angle than the contra-standard sculling (2.4 ± 0.3 vs. 2.0 ± 0.2 cycles/s and 134.1 ± 5.8 and 141.5 ± 4.7°, p < 0.05). In the standard sculling, by removing and maintaining the variation between participants (r w and r, respectively), the absolute mean force was directly related with cycle rate (r w  = 0.60) and wrist angular velocity during flexion (r = 0.82), while in the contra-standard condition the force was inversely associated with wrist mean angle (r = -0.95) and directly with hand speed (r w  = 0.76), and elbow angular velocity (r w  ≈ 0.60). Therefore, technique learning and training require different attention by coaches and swimmers.

Assuntos

RESUMO

Em esportes aquáticos, pode-se avaliar a força propulsiva gerada para deslocar-se por meio do nado estacionário (sem deslocamento) ou por meio do nado semiestacionário (com deslocamento). A maioria dos estudos realizados utiliza cabo de aço para prender o sujeito. Encontram-se também alguns estudos utilizando tubo elástico, contudo é citada a possibilidade do tubo dissipar força. Assim, o objetivo deste trabalho foi comparar as características da curva de força gerada pelo palmateio propulsivo na posição de frente direção cabeça, estando o indivíduo preso a diferentes materiais: tubo elástico e cabo de aço. A amostra foi composta por 10 voluntários, com minimamente um ano de experiência no gesto (idade 21,3 ± 5,98 anos, tempo de treinamento 10,10 ± 6,19 anos). Cada indivíduo executou o palmateio em força máxima por 30 s, amarrado ao material, ligando-o a uma célula de carga fixada na borda da piscina. As forças máxima, máxima relativa, inicial e o índice de fadiga foram maiores no nado estacionário; a força média final, impulso e tempo para força máxima foram maiores no nado semiestacionário. Apenas a força média não apresentou diferença significativa, indicando que a curva de força durante o palmateio tende a ser diferente dependendo do material utilizado...(AU)

In aquatics sports, one can evaluate the propulsive force generated to move through tethered swimming (without displacement) or through semitethered swimming (with displacement). Most studies use wire rope to attach the individual. There are also some studies using elastic tube however is mentioned the possibility of dissipating tube strength. The purpose of this study was to compare the characteristics of the curve sculling propulsive force generated by the sculling towards the head, in different materials: elastic tube and wire rope. The sample consisted of 10 volunteers, with at least one year of experience in the task (age 21.3 ± 5.98 years, training time 10.10 ± 6.19 years). Each participant performed the sculling at maximum force for 30 s, tied to the material, which was attached to a load cell fixed in the edge of the pool. The maximum, relative maximum and initial forces and fatigue index were higher in tethered swimming, the average and final forces, impulse and time to maximum force were higher in semitethered swimming. Indicating that the force curve during the sculling tends to be different depending on the material use...(AU)

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RESUMO

O objetivo deste estudo foi analisar a reprodutibilidade dos parâmetros biomecânicos da curva força-tempo do estilo "Crawl" em um protocolo de 10 s no nado atado. Dezesseis nadadores do sexo masculino (idade: 20,4 ± 4,0 anos; tempo na prova de 100 m livre: 53,68 ± 0,99 s) realizaram dois esforços máximos de 10 s no nado atado. Os parâmetros força pico, força média, taxa de desenvolvimento de força, impulso, duração da braçada, tempo para atingir a força pico e força mínima foram representados pela média de oito braçadas consecutivas obtidas em cada tentativa. Utilizou-se o teste t para observar as diferenças entre os esforços para cada parâmetro. O nível de significância estabelecido foi de 5%. A reprodutibilidade relativa foi medida pelo coeficiente de correlação de Pearson e a consistência entre as duas tentativas pelo coeficiente de correlação intraclasse (CCI). A reprodutibilidade absoluta foi verificada pelo coeficiente de variação (CV). Não foi demonstrada diferença estatisticamente significante para nenhum parâmetro biomecânico quando comparados os dois esforços. Os elevados CCI e baixos CV indicaram alta consistência interna dos parâmetros analisados. Conclui-se que os parâmetros biomecânicos analisados a partir do nado atado são reprodutíveis quando empregado protocolo de curta duração o que demonstra a possibilidade de utilização do protocolo com alto grau de confiabilidade, por parte de treinadores e atletas.

The aim of the present study was to analyze the reliability of biomechanical parameters of the front-Crawl's force-time curve in a 10-s protocol. Sixteen national competitive male swimmers (20.4 ± 4.0 years; 100-m best time: 53.68 ± 0.99 s) performed two 10-s maximal efforts in tethered swimming. Peak force, average force, impulse, rate of force development, stroke duration, time to peak force and minimum force were represented by the mean of eight consecutive strokes obtained in each trial. The paired student-t test was used to verify differences between trials for each biomechanical parameter. The significance level adopted was 5%. Relative reliability was tested by Pearson correlation coefficient and the consistency between trials by means of intraclass coefficient (CCI). The coefficient of variation was used to verify the absolute reliability. No significant differences between the trials to any biomechanical parameter were found. High CCI values and low CV values revealed the high internal consistency of the analyzed variables. It can be concluded that the biomechanical parameters regarding the tethered swimming are reliable in short duration protocols and may be used by coaches and athletes for monitoring training.

Assuntos

RESUMO

O objetivo deste estudo é relacionar o desempenho (DES) em 200m nado crawl e variáveis cinéticas do teste de nado estacionário (TNE): impulso total (IMP), taxa de variação de impulso (TIMP) e pico de força (PF). De 12 nadadores competitivos (idade média de 18,3 ± 2,9 anos) foram obtidos IMP, TIMP, PF e DES em 200m nado crawl (este transformado em unidades pontuais). Com o desempenho (711,8 ± 29,1 pontos), o IMP (2663,6 ± 150,6 N·s) apresentou correlação (r = 0,876; p < 0,001), enquanto a TIMP (-24,45 ± 14,38 N) e o PF (217,48 ± 29,10 N) não apresentaram correlações (r = -0,553; p = 0,062 e r = -0,19; p= 0,714; respectivamente). O impulso total obtido no TNE pode ser utilizado como parâmetro de avaliação da capacidade de força aplicada ao longo do tempo e como preditor do desempenho na prova de 200m nado livre.

The purpose of this study is to relate 200 m front crawl performance (DES) and kinetics variables obtained from a tethered swimming test (TNE): total impulse (IMP), impulse rate (TIMP) and force peak (PF). From 12 competitive swimmers (mean age: 18.3 ± 2.9 years) were obtained IMP, TIMP, PF and DES in 200 m front crawl (this last transformed into unit points). Regarding to DES (711.8 ± 29.1 points): IMP (2663.6 ± 150.6 N·s) was significantly correlated (r = 0.876; p < 0.001), whereas TIMP (-24.45 ± 14.38 N) and PF (217.48 ± 29.1 N) were not correlated (r = -0.553; p = 0.062 and r = -0.19; p = 0.714, respectively). Total impulse obtained from TNE can be used a force capacity along time assessment parameter and as a performance parameter predictor for the 200 m freestyle event.

O objectivo del estudo es relacionar el desempeño (DES) en 200m nado crol y variables cinéticas del test de nado estacionario (TNE): impulso total (IMP), tasa de variación de impulso (TIMP) y pico de fuerza (PF). De 12 nadadores competitivos (edad: 18,3 ± 2,9 anos) se obtuvieron IMP, TIMP, PF y DES en 200 m nado crol (éste convertido en unidades puntuales). Con el desempeño (711,8 ± 29,1 puntos): IMP (2663,6 ± 150,6 N·s) presentó correlación (r = 0,876; p < 0,001), mientras TIMP (-24,45 ± 14,38 N) y PF (217,48 ± 29,10 N) no presentaron correlaciones (r = -0,553; p = 0,062 y r = -0,19; p= 0,714; respectivamente). El impulso total obtenido en el TNE se puede utilizar como parámetro de evaluación de la capacidad de fuerza aplicada a lo largo del tiempo y como predictor del desempeño en la prueba de 200 m nado libre.

RESUMO

The present study investigated the relationship of critical force (Fcrit) with lactate threshold (LLNA) and the intensity corresponding to VO2max (iVO2max) in tethered swimming (TS), and their correlation with maximal performance in 400-m (V400) and 30-min (VT30) freestyle swimming (FS). Seven swimmers were submitted to a TS incremental test for the determination of LLNA and iVO2max. For the determination of Fcrit, the swimmers performed four exercises to exhaustion at intensities (F) corresponding to 87%, 104%, 118% and 134% of iVO2max for the calculation of time limits (Tlim). Fcrit corresponded to the linear coefficient of the ratio between F and 1/tlim. The maximal performance in FS corresponded to the mean velocity obtained during maximal exercise of 400-m and 30-min crawl swimming. Fcrit (51.97 ± 4.02 N) was significantly lower than iVO2max (60.21 ± 8.73 N) but not than LLNA (45.89 ± 8.73). Fcrit was significantly correlated with iVO2max (0.97), LLNA (0.88), V400 (0.85), and VT30 (0.86). These data suggest that Fcrit can be used for the determination of aerobic capacity, prescription of a TS training program, and prediction of performance in FS.

The present study investigated the relationship of critical force (Fcrit) with lactate threshold (LLNA) and the intensity corresponding to VO2max (iVO2max) in tethered swimming (TS), and their correlation with maximal performance in 400-m (V400) and 30-min (VT30) freestyle swimming (FS). Seven swimmers were submitted to a TS incremental test for the determination of LLNA and iVO2max. For the determination of Fcrit, the swimmers performed four exercises to exhaustion at intensities (F) corresponding to 87%, 104%, 118% and 134% of iVO2max for the calculation of time limits (Tlim). Fcrit corresponded to the linear coefficient of the ratio between F and 1/tlim. The maximal performance in FS corresponded to the mean velocity obtained during maximal exercise of 400-m and 30-min crawl swimming. Fcrit (51.97 ± 4.02 N) was significantly lower than iVO2max (60.21 ± 8.73 N) but not than LLNA (45.89 ± 8.73). Fcrit was significantly correlated with iVO2max (0.97), LLNA (0.88), V400 (0.85), and VT30 (0.86). These data suggest that Fcrit can be used for the determination of aerobic capacity, prescription of a TS training program, and prediction of performance in FS.