Potencia muscular en relación a la composición corporal en jugadores de voleibol adolescentes según género / Muscle power in relation to body compositionin adolescent volleyball players according to gender

RESUMEN Objetivo: analizar si existe diferencia en la composición corporal por género y si esta influye sobre el rendimiento físico de jugadores de vóleibol adolecentes. Método: se agruparon veinticinco jugadores de vóleibol (Hombres n = 10, Mujeres n = 15). Se midió la composición corporal y potencia muscular mediante la prueba de salto en contra movimiento y remate de balón. Resultados: se observó que los hombres presentaban una mayor masa muscular junto a una menor grasa corporal relacionada a un mayor rendimiento en las pruebas de rendimiento físico. Conclusión: los hombres presentan una mayor masa muscular y menor grasa corporal junto a un mejor rendimiento en las pruebas de potencia muscular.

ABSTRACT Objective: analyze if there is a difference in body composition by gender and if this influences the physical performance of adolescent volleyball players. Method: twenty-five adolescent volleyball players (Men n = 10, Women n = 15) were grouped together. Body composition and muscle power were measured using the countermovement jump test and volleyball spike. Results: the observations were that men had greater muscle mass together with lower body fat related to higher performance in physical performance tests. Conclusion: men have greater muscle mass and lower body fat along with better performance in muscle power tests.

Effect of warm-up on hand grip strength in sedentary overweight women / Efecto del calentamiento en la fuerza de agarre de mano en mujeres sedentarias con sobrepeso

Abstract Introduction: In recent years, handgrip strength assessment has gained special relevance in health. However, a standardized application protocol that includes warm-up procedures is required to measure it. Objective: To compare the acute effects of four warm-up strategies on maximal handgrip strength (MHS) in sedentary overweight women. Materials and methods: Single-blind, randomized, crossover study in which MHS was measured in 12 overweight women under the following conditions: i) no warm-up (control condition), ii) static stretching warm-up, iii) strength-based warm-up (i.e., resistance band exercise), and iv) isometric squeezing-ball warm-up for the forearm muscles. A Jamar dynamometer was used for the measurements, which were taken on four different days, at 48-hour rest intervals; three measurements were made per hand. Results: MHS mean values were 23.8 and 24.9 kg without warm-up, 20.3 and 21.4 kg after stretching warm-up, 20.9 and 22.9 kg after strength-based warm-up, and 22.0 and 23.0 kg after squeezing-ball warm-up for non-dominant and dominant hand, respectively. No significant differences (p>0.05; one-way ANOVA) were observed between protocols, nor were there differences in MHS in relation to nutritional status, lean mass, or fat mass. Conclusion: Warm-up is not required to measure MHS in overweight sedentary women when three measurements are made.

Resumen Introducción. En los últimos años se ha dado una mayor importancia a la medición de la fuerza máxima de agarre de mano, sin embargo para hacer esta medición se requiere un protocolo estandarizado de aplicación, incluyendo procedimientos de calentamiento. Objetivo. Comparar los efectos agudos de cuatro tipos de calentamiento en la fuerza máxima de agarre de mano de mujeres sedentarias con sobrepeso. Materiales y métodos. Estudio ciego, aleatorizado y cruzado en el que se midió la fuerza máxima de agarre de mano de 12 mujeres con sobrepeso bajo las siguientes condiciones: i) sin calentamiento (condición de control), ii) con calentamiento de estiramiento estático, iii) con calentamiento basado en la fuerza (p. ej., ejercicios con banda elástica) y iv) con calentamiento con bola terapéutica de compresión para los músculos del antebrazo. Para las mediciones se utilizó un dinamómetro Jamar y estas se realizaron en cuatro días diferentes y en intervalos de 48 horas de descanso; además, se hicieron tres intentos de medición por mano. Resultados. Los valores promedio de fuerza máxima de agarre para la mano no dominante y dominante fueron 23.8kg y 24.9kg sin calentamiento, 20.3kg y 21.4kg con estiramiento, 20.9kg y 22.9kg con banda elástica y 22.0kg y 23.0kg con bola terapéutica, respectivamente. No hubo diferencias significativas (p>0.05; ANOVA de una vía) entre los protocolos, ni diferencias en la fuerza máxima de agarre de mano en relación con estado nutricional, masa magra o masa grasa. Conclusión. No se requiere una sesión de calentamiento para medir la fuerza máxima de agarre de mano en mujeres sedentarias con sobrepeso cuando se realizan tres intentos de medición.

Body composition of male and female Chilean powerlifters of varying body mass

Aim: To examine body composition of Chilean powerlifters according to body mass and sex. Methods: Fifty-six male and female powerlifters were recruited from one national competition. Aside from the official weight categories, males were classified as the lightweight, middleweight, and heavyweight classes. Similarly, females were classified as lightweight and middle-heavyweight classes. Nineteen anthropometric measures were assessed, with lean mass as the main outcome. A one-way ANOVA was used to compare groups. Results: Male lightweight class lifted less (p<0.01) total load (417±30.9 kg) compared to heavier male classes (524±66.7 kg, middleweight; 581±131 kg, heavyweight), and female classes lifted less (p<0.01) total load (221±33.8 kg, lightweight; 254±48.3 kg, middleweight-heavyweight) compared to all male classes. Regarding lean-mass in trunk, arms and legs, total body protein, water, and mineral mass, all male groups had greater (p<0.01) values than the groups of females, while lightweight males had lower (p<0.01) values than the rest of male groups, and heavyweight males had greater (p<0.01) values than the total sample of males (except for legs lean mass, and total bone mineral content). In females, no significant differences were observed between classes, or in total load lifted or in body composition. Conclusion: Heavier male lifters had significantly greater lean mass than lighter athletes. Therefore, powerlifting performance was affected by anthropometric measures, as corroborated by 1-RM scores. However, there was a general lack of differences in body composition between female weight classes, and, as a result, a lack of differences in 1RM performance.(AU)

Association of maximal voluntary isometric handgrip strength with age, gender and handedness in older people / Fuerza de agarre isométrica máxima en relación a la edad, sexo y dominancia de mano

ABSTRACT Background: Maximal voluntary isometric handgrip strength (MVIHS) is influenced by age, sex, and handedness. Aim: To assess the association of MVIHS with age, sex, and handedness in older adults. Material and Methods: MVIHS was measured using a digital dynamometer in 60 men and 60 women aged 73 ± 6 years. Weight, height and handedness were also recorded. For analysis purposes, participants were divided into two age groups (65 to 70.9 years of age and ≥ 71 years). Results: A negative correlation was observed between age and MVIHS in the non-dominant (r = −0.65 and −0.59 in men and women, respectively) and dominant hands (r = −0.71 and −0.64 in men and women, respectively). When age and MVIHS were correlated in the group aged 65-70 years, a significant correlation was observed in the non-dominant (r = −045 and −0.61 in men and women, respectively) and dominant hands (r = −0.47 and −0.64 in men and women, respectively). In the group aged ≥ 71 years, a stronger correlation with age was also observed in the non-dominant (r = −0.92 and −0.90 in men and women, respectively) and dominant hands (r = −0.95 and −0.90 in men and women, respectively). MVIHS was 2.8 to 8.9% lower in the non-dominant than in the dominant hand in all age groups. MVIHS was lower in women than in men in both age groups. Conclusions: MVIHS declines with age (especially after 71 years of age), is higher in men than women, and higher in the dominant than the non-dominant hand.

Antecedentes: La fuerza de agarre isométrica voluntaria máxima (FAIVM) puede verse influenciada por la edad, el sexo y la dominancia. Objetivo: Describir la FAIVM y su relación con la edad, el sexo y la dominancia en adultos mayores. Material y Métodos: La FAIVM, la masa corporal, la talla, y la dominancia fueron medidas mediante protocolos estandarizados en 60 hombres e igual número de mujeres que fueron divididos en dos grupos acorde a su edad (65 a 70,9 años, y ≥ 71 años, respectivamente). Resultados: Se observó una correlación entre la edad y la FAIVM de mano no-dominante (hombres: r = −0,65; mujeres: r = −0,59) y dominante (hombres: r = −0,71; mujeres: r = −0,64). Al correlacionar la FAIVM y la edad en el grupo de 65-70 años, una correlación significativa fue observada en la mano no-dominante (hombres, r = −0,45; mujeres, r = −0,61) y mano dominante (hombres, r = −0,47; mujeres, r = −0,64). En el grupo ≥ 71 años, la edad tuvo una mayor correlación con la FAIVM de la mano no-dominante (hombres, r = −0,92; mujeres, r = −0,90) y mano dominante (hombres, r = −0,95; mujeres, r = −0,90). Comparada con la mano dominante, la mano no-dominante presentó menores valores de FAIVM en todos los grupos, variando entre −2,8 a −8,9%. Comparadas con los hombres, las mujeres presentaron menor FAIVM en mano dominante y no-dominante, en ambos grupos de edad. Conclusión: La FAIVM disminuye con la edad, especialmente desde los 71 años; es mayor en hombres comparados con mujeres y es mayor en mano dominante comparada con mano no-dominante.