Effects of combined and classic training on different isometric rate of force development parameters of leg extensors in female volleyball players: Discriminative analysis approach.

BACKGROUND: The aim of this study is to verify the effects of the combined and classic training of different isometric rates of force development (RFD) parameters of legs. MATERIALS AND METHODS: THREE GROUPS OF FEMALE ATHLETES WAS TESTED: Experimental group (N = 12), classically trained group (N = 11), and control group (N = 20) of athletes. The isometric "standing leg extension" and "Rise on Toes" tests were conducted to evaluate the maximal force, time necessary time to reach it and the RFD analyzed at 100 ms, 180 ms, 250 ms from the onset, and 50-100% of its maximal result. RESULTS: The maximal RFD of legs and calves are dominant explosive parameters. Special training enhanced the RFD of calves of GROUPSPEC at 100 ms (P = 0.05), at 180 ms (P = 0.039), at 250 ms (P = 0.039), at 50% of the Fmax (P = 0.031) and the Fmax (P = 0.05). Domination of GROUPSPEC toward GROUPCLASS and GROUPCONTROL is in case of legs at 100 ms (P = 0.04); at 180 ms (P = 0.04); at 250 ms (P = 0.00); at 50% of the Fmax (P = 0.01) and at the Fmax (P = 0.00); in case of calves at 100 ms (P = 0.07); 180 ms (P = 0.001); at 250 ms (P = 0.00); at 50% of the Fmax (P = 0.00) and at Fmax (P = 0.000). CONCLUSION: Dominant explosive factors are maximal RFD of leg extensors and calves, and legs at 250ms. Specific training enhanced explosiveness of calves of GROUPSPEC general and partial domination of GROUPSPEC by 87% over GROUPCLASS, and 35% over GROUPCONTROL.

Nutritional status and blood pressure in adolescent students.

INTRODUCTION: Obesity is the main risk factor for arterial hypertension andis associatedwitha higher morbidity, both in the short and long term. OBJECTIVES: To compare anthropometric and blood pressure indicators in terms of the nutritional status, to verify the relationship between nutritional status and blood pressure, and to establish the prevalence of hypertension in terms of the nutritional status in both male and female adolescents. METHODS: Cross-sectional, descriptive study on 499 adolescent students aged 11-15 years old. Weight, height, body mass index (BMI), fat percentage, and blood pressure were measured and assessed. The BMI was used to classify participants (normal weight, overweight, obese), and the prevalence of hypertension was determined using values above the 95th percentile. RESULTS: As per the BMI classification, 81% of girls and 76.5% ofboys had normal weight, 15.7% of girls and 15.5% of boys were overweight, and 3.3% of girls and 8% of boys were obese. As per the blood pressure classification, hypertension was observed in 6.4% of boys and in 9% of girls. A relationship was found between nutritional status and blood pressure (boys: c2= 53.48; girls: c2= 85.21). CONCLUSION: Overweight and obese adolescents had more body fat and a higher blood pressure than normal weight adolescents. Also, a relationship was determined betweennutritional status and blood pressure in both male and female students. The higher the BMI, the higher the prevalence of hypertension.

RELATIONSHIP BETWEEN TRAINING VOLUME AND BONE MINERAL DENSITY CHANGES IN ELDERLY WOMEN / RELAÇÃO ENTRE O VOLUME DE TREINAMENTO E MUDANÇAS DE DENSIDADE MINERAL ÓSSEA EM MULHERES IDOSAS / RELACIÓN ENTRE VOLUMEN DE ENTRENAMIENTO Y CAMBIOS EN LA DENSIDAD MINERAL ÓSEA EN MUJERES MAYORES

ABSTRACT Introduction: Several studies have analyzed the relationship between physical activity and bone density. However, the prescription of exercise is not entirely clear as to the type, quantity and intensity. Objective: The objective of this study was to determine if there is a relationship between the amount of exercise and changes in bone mineral density. Methods: Fifty-two women, members of the Municipal Program of Physical Activity for Seniors, voluntarily underwent two ultrasonographies of the calcaneus within a 6-month interval. During this period, all physical activity was recorded. Afterwards, a lineal correlation study was carried out between the amount of exercise and bone changes, expressed as T-Score variation, first in total number of participants and then in groups. Considering the average body weight obtained for all women, two groups were created ("light" < 69 kg and "heavy" > 69 kg). Later, women who had participated in less than 72% of the targeted program were excluded from both groups, and the differences between the groups "light and trained" and "heavy and trained" were analyzed. To do so, the nonparametric Mann-Whitney U test was used. Results: A significant relationship of r= -0.59 was found between the total amount of exercise and the T-Score variation in the group of women above 69 kg. Significant differences were found between the "light and trained" group and the "heavy and trained" group with respect to the variation of T-Score. Conclusion: The effect of exercise on bone mineral density is determined, somehow, by body weight. This interaction is due, possibly, to mechanical demands difference.

RESUMO Introdução: Vários estudos analisaram a relação à quantidade de atividade física e densidade óssea. No entanto, a prescrição de exercício físico não é totalmente clara, em relação ao tipo, quantidade e intensidade. Objetivos: o objetivo deste estudo foi determinar se existe relação entre a quantidade de exercício físico e alterações na densidade óssea. Métodos: 52 mulheres, membros do programa municipal de atividade física para idosos participaram voluntariamente na realização de dois ultrassonografias de calcâneo, separado 6 meses. Durante este período, toda a atividade física foi registrada. Em seguida, foi realizado um estudo de correlação linear entre a quantidade de exercício físico e alterações ósseas, expressos como variação do T-Score, primeiro de maneira conjunta e despois em grupos. Considerando-se o peso corporal médio obtido para todas as mulheres, dois grupos foram criados ("magro" < 69Kg e "pesado" > 69Kg). Mais tarde, as mulheres que tinham participado em menos do 72% do programa alvejado foram excluídas de ambos os grupos, e foram analisadas as diferenças entre o grupo "magro e treinado" e o grupo "pesado e treinado". Para alcançar este objetivo, foi utilizado o teste não paramétrico da U de Mann-Whitney. Resultados: foi encontrada ama relação significativa de r = -0,59 entre a quantidade total do exercício físico e da variação do T-Score, no grupo das mulheres de mais do que 69Kg. Foram encontradas diferenças significativas entre o grupo "magro y treinado" e o grupo "pesado e treinado", em relação à variação do T-Score. Conclusão: o efeito do exercício físico na densidade mineral óssea é determinado de alguma forma, pelo peso corporal. Esta interação é possivelmente devida à diferente demanda mecânica.

RESUMEN Introducción: Diversos estudios han analizado la relación entre la actividad física y la densidad ósea. Sin embargo, la prescripción de ejercicio físico no está completamente clara en relación al tipo, cantidad e intensidad. Objetivo: El objetivo de este estudio fue determinar si existe relación entre la cantidad de ejercicio y los cambios en la densidad mineral ósea. Métodos: Cincuenta y dos mujeres, integrantes del Programa Municipal de Actividad Física para Mayores, participaron voluntariamente en la realización de dos ultrasonografías de calcáneo, con intervalo de 6 meses. Durante este periodo, se registró toda la actividad física. A continuación, se realizó un estudio de correlación lineal entre la cantidad de ejercicio y cambios óseos, expresados como la variación del T-Score, primero de forma conjunta y posteriormente por grupos. Teniendo en cuenta el peso corporal medio obtenido para el total de mujeres, se crearon dos grupos ("ligero" < 69 Kg y "pesado" > 69 Kg). Más tarde, las mujeres que habían participado en menos del 72% del programa dirigido fueron excluidas de ambos grupos y se analizaron las diferencias entre el grupo "ligero y entrenado" y el grupo "pesado y entrenado". Para lograr este objetivo, se utilizó la prueba no paramétrica de la U de Mann-Whitney. Resultados: Se encontró una relación significativa de r= -0,59 entre la cantidad total de ejercicio físico y la variación del T-Score en el grupo de mujeres de más de 69 Kg. Se encontraron diferencias significativas entre el grupo "ligero y entrenado" y el grupo "pesado y entrenado" con respecto a la variación del T-Score. Conclusión: El efecto del ejercicio físico sobre la densidad mineral ósea está determinado, de alguna manera, por el peso corporal. Esta interacción es debida posiblemente a la diferente demanda mecánica.

Valoración del crecimiento físico por medio de la proporcionalidad corporal en escolares peruanos que viven a moderada altitud / Assessment of physical growth through body proportionality in Peruvian children living at moderately elevated altitudes

La estrategia del Phantom es un instrumento para medir la proporcionalidad corporal que permite comparar el crecimiento de los segmentos y dimensiones corporales. El objetivo del presente estudio radica en valorar el crecimiento físico por medio de la proporcionalidad corporal de escolares de 6 a 12 años que viven a moderada altitud. El estudio es de tipo descriptivo Transversal. Participaron de la investigación 482 damas y 473 varones de 6 a 12 años de condición socioeconómica media. Los escolares fueron seleccionados de forma probabilística estratificada de un total de 6659 alumnos. Se evaluó las medidas antropométricas de peso (kg), estatura (m), cinco pliegues cutáneos (mm), cuatro circunferencias corporales y cuatro diámetros óseos. El análisis de la proporcionalidad se efectuó por medio del modelo teórico del Phantom propuesto por Ross y Wilson (1974). Los resultados del Z-escore del Phantom para ambos géneros muestran valores negativos de forma general para el peso corporal (-3,7 a -1,7), pliegues cutáneos (0,5 a -1,5) y circunferencias corporales (-0,9 a -1,3). A su vez, los diámetros óseos evidencian valores positivos en todas las edades y en ambos géneros (1,0 a 3,2). Los resultados sugieren que los escolares de moderada altitud se caracterizan por presentar un lento crecimiento respecto al peso corporal, pliegues cutáneos y circunferencias corporales y en relación a los diámetros óseos muestran una tendencia a la robustez.

The strategy of our approach involves the use of an instrument for measuring body proportionality for the purpose of comparing growth of segments to body dimensions. The objective of this descriptive transversal study is to assess physical growth through body proportionality of school children, aged 6 to 12 years, living at moderately elevated altitudes. Study participants included 482 females and 473 males ranging in ages from 6 to 12 years and possessing middle socioeconomic status. The students were selected from a stratified probability segment of 6,659 students. In all, we evaluated: anthropometric measurements of weight (kg), height (m), five skinfolds (mm), four body perimeters and four body-bone diameters. Proportionality analyses were performed using the Phantom theoretical model proposed by Ross and Wilson (1974). The results of the Phantom Z-scores for both genders show generally negative values for body weight (-3.7 to -1.7), skinfold thickness (0.5 to -1.5), and body circumference (-0.9 to -1.3). In turn, bone diameters show positive values in all ages as well as in both genders (1.0 to 3.2). The results suggest that school children living at moderately elevated altitudes are characterized by slow growth correlated to body weight; on the other hand, skinfold thicknesses and body circumferences in relation to bone diameters exhibit a tendency to robustness.