ABSTRACT
O objetivo deste estudo foi o de desenvolver e validar um teste para estimar a potência aeróbia de jovens tenistas do sexo masculino. A amostra foi composta por 24 tenistas competitivos com média de idade de 15.58 ± 1.77 anos, os quais foram submetidos a dois tipos de testes máximos e diretos, um específico na quadra de tênis, e outro em esteira rolante no laboratório. A normalidade dos dados foi analisada pelo teste de Shapiro-Wilk. O teste "t" pareado para análise das diferenças entre cada teste bem como o teste de campo e o seu reteste. Correlação de Pearson analisou a relação do teste de laboratório com o de campo, e também entre o teste e o reteste de campo. O poder de explicação das variáveis preditoras do VO2 para o teste de campo foi determinado pela regressão linear simples e pelo coeficiente de correlação intraclasse. Os resultados evidenciaram diferenças significativas para as variáveis, tempo total, distância percorrida, pico de consumo de oxigênio (VO2pico) e quociente de trocas respiratórias entre o teste de campo e o de laboratório: correlação moderada entre o teste de campo e o de laboratório (r=0.539; p<0.05) para a variável VO2pico, e correlação moderada entre o VO2pico e a frequência cardíaca máxima obtidos no teste de campo (r=0.417; p<0.05), propondo uma equação preditiva do VO2pico (VO2pico= -15.125 + [0.334 x FCmáx]). Pode-se concluir que o teste proposto foi válido e pode ser utilizado para estimar a potência aeróbia de jovens tenistas de competição do sexo masculino...(AU)
The aim of this study was to develop and validate a test to estimate on court aerobic of competitive tennis players. The sample consisted of 24 competitive male tennis players (federate and/or confederate), with age average of 15.58 ± 1.77 years. They were be subject to the assessment of two types of maximal tests, a specific field test on the tennis court and the other conducted in a treadmill laboratory (gold standard), both with direct measurement of oxygen consumption (VO2). For the analysis of the blood lactate concentration, was used Accutrend® lactometer (ROCHE). The sample was characterized by descriptive statistics and measures of central tendency. The Shapiro Wilk test was applied to verify the data normality. The analyzes of differences between each test, and the test proposed and its retest is given by using the "t" paired test. The Pearson correlation coefficient (r) was used to analyze the relationship between the treadmill test with the court, and also between test and re-test. The explanatory power of predictor variables of VO2 for the specific test was determined by simple linear regression and the intraclass correlation coefficient (ICC), with a confidence interval of 95% applied to obtain the criteria of significance measures of the specific test. The statistical program used was SPSS 20.0. The results showed a moderate correlation between the proposed test and the laboratory (r = 0.539, p<0.05) for VO2peak variable, and a moderate correlation between VO2peak_court and Maximal Heart Rate_Court (r = 0.417, p<0.05), making it possible to propose a predictive equation by MHR variable obtained in the court test (VO2peak = -15.125 + (0.334 x MHR). Thus, it can be concluded that the proposed test was valid and can be used to estimate the aerobic power (VO2peak) in young male competitive tennis players...(AU)
Subject(s)
Humans , Male , Adolescent , Adolescent , Efficiency , Exercise Test , Tennis , Validation Study , MentoringABSTRACT
Tennis is a sport that requires asymmetric movements of dominat limbs and may lead to an asymmetric distribution of muscle mass. The main aim of the presented study was to determine the volume and degree of lateral asymmetry of the upper and lower limbs in youth tennis players using a bioelectrical impedance analysis. T-test was applied to find differences between the dominant and non-dominant arm and the right and left leg and thigh in four age categories. There were no significant differences between the right and left leg lean mass in the 12 and under, 14 and under and 16 and under age groups, but there were significant differences between the dominant and non-dominant arm lean mass and arm circumferences in all four age groups. All young tennis players had greater lean mass and arm circumferences of the dominant limb. Tennis players in the 18 and under group had higher average values of right leg lean mass and the differences are statistically significant. There were significant differences between right and left thigh circumferences in all age groups. Findings show that it is possible with such a simple, non-invasive and quick procedure as bioelectrical impedance to determine asymmetry in tennis players.
El tenis es un deporte que requiere movimientos asimétricos de los miembros dominantes y puede conducir a una distribución asimétrica de la masa muscular. El objetivo fue determinar el volumen y grado de asimetría lateral de los miembros superiores e inferiores en tenistas juveniles utilizando un análisis de impedancia bioeléctrica. Se aplicó la prueba T para encontrar diferencias entre el brazo dominante y no dominante y las piernas y muslos derecho e izquierdo en cuatro categorías de edad. No hubo diferencias significativas en la masa magra de las piernas derecha e izquierda en los grupos de edad: 12 y menor, 14 y menor, y 16 y menor. Sin embargo, hubo diferencias significativas en la masa magra de las circunferencias de los brazos dominante y no dominante en los cuatro grupos de edad. Todos los jugadores jóvenes de tenis tenían mayor masa magra en las circunferencias de los brazos del miembro dominante. Los jugadores de tenis en el grupo de 18 años y menor, tenían valores medios más altos de masa magra de la pierna derecha, con diferencias estadísticamente significativas. No hubo diferencias significativas entre las circunferencias de los muslos derecho e izquierdo en todos los grupos de edad. Los resultados muestran que es posible determinar con un procedimiento simple no invasivo y rápido, como la impedancia bioeléctrica, la asimetría en jugadores de tenis.
Subject(s)
Humans , Male , Child , Adolescent , Electric Impedance , Lower Extremity/anatomy & histology , Tennis , Upper Extremity/anatomy & histology , Age FactorsABSTRACT
Several studies have examined both physical characteristics and fitness of children and youth. The aim of the study was first, to find the tendency of changes in selected morphological characteristics of young male and female tennis players of various ages in the periods 1992-2000-2008; and second, to find the changes in selected variables of young tennis players and to compare them with the results of boys and girls of same age from normal school population. Sample of variables included body height, body weight and body mass index (BMI). Multivariate analysis of variance revealed statistically significant differences in all main factors (group, age, gender and period) and additionally in interactions group*period, group*gender and age*gender. Univariate analysis of variance revealed statistically significant differences in body height and BMI between the groups of tennis players and the same age school population for both sexes and between three age groups (12-13 years, 14-15 years, 16-17 years) for body height, body weight and BMI. Differences between the sexes indicate statistically significant differences only in variables body height and weight. Changes in the observed morphological characteristics point to the increase in body height, body weight and BMI values in both school population and young tennis players.
Diversos estudios han examinado las características y estado físico de niños y jóvenes. El objetivo de este estudio fue encontrar la tendencia de los cambios para determinadas características morfológicas de jóvenes tenistas (hombres y mujeres) de distintas edades, en los períodos 1992-2000-2008. Además, encontrar cambios en las variables seleccionadas de jugadores de tenis jóvenes y compararlos con los resultados de niños y niñas de la misma edad en la población escolar normal. Las variables de la muestra incluyeron altura y peso corporal e índice de masa corporal (IMC). El análisis multivariado de varianza reveló diferencias estadísticamente significativas en todos los factores principales (grupo, edad, sexo y periodo) y, además, en las interacciones de grupo-período, grupo-edad y grupo-sexo. El análisis univariado de varianza reveló diferencias estadísticamente significativas en la altura corporal e IMC entre los grupos de jugadores de tenis y la misma población en edad escolar para ambos sexos y entre los tres grupos de edad (12-13 años, 14-15 años, 16-17 años) para altura y peso corporal e IMC. Las comparación entre sexos indican diferencias estadísticamente significativas sólo en las variables altura y peso corporal. Los cambios en las características morfológicas observadas señalan un aumento de la altura y peso corporal e IMC tanto en la población escolar como en los jóvenes jugadores de tenis.