ABSTRACT
Eurycoma longifolia Jack (ELJ) is a herbal plant that has androgenic and antioxidant effects. We investigated the short-term effect of ELJ supplementation on muscle damage induced by eccentric exercise. Eighteen young (19-25 years), well-trained rugby 7s players were assigned to an ELJ or a placebo (PLA) group (n = 9/group). Each participant took four 100-mg capsules a day for seven days prior to performing a leg press eccentric exercise to failure in a double-blind fashion. Peak force, peak power and jump height in countermovement jump (CMJ), drop jump reactive strength index (RSI), muscle soreness assessed by a 100-mm visual analogue scale, plasma creatine kinase (CK) activity, and salivary hormones were measured at 24 h before and 0.5, 24, 48, 72, and 96 h after the exercise. Changes in the variables over time were compared between the groups by two-factor mixed-design ANOVA. The number of eccentric contractions performed was similar (P = 0.984) between the ELJ (21 ± 5) and PLA groups (21 ± 5). Salivary testosterone and cortisol concentrations did not change (P > 0.05) after the supplementation for both groups. CMJ peak power (-9.4 ± 5.6%) and height (-10.6 ± 4.9%), and RSI (-15.2 ± 16.2%) decreased at 24 h after exercise (P < 0.05), and muscle soreness (peak: 89 ±10 mm) and plasma CK activity (peak: 739 ± 420 IU/L) increased after exercise (P < 0.05) without significant differences between groups. These results showed that 7-day ELJ supplementation prior to the leg press eccentric exercise had no significant effects on hormones, performance and muscle damage markers for the athletes.
ABSTRACT
This study aimed to compare jump-related performance after plyometric training on harder vs. softer surfaces in rugby sevens players. Fourteen players were randomly assigned to the harder surface group (H-G, n = 7) and softer surface group (S-G, n = 7). Three times per week, in the morning, the players performed plyometric training on different surfaces and strength training. Before and after the 4-week intervention period, squat jump (SJ), countermovement jump (CMJ), and CMJ with arms (CMJA) tests were performed to measure vertical jump displacement (d), rate of force development (r), and power (p). The main results indicated a significant improvement in S-G for CMJd (∆% = +8.2%; p = 0.029; ES = 0.59) and for CMJAp (∆% = +8.7%; p = 0.035; ES = 0.44). These improvements were significant compared to H-G for CMJAd (F1,12 = 8.50; p = 0.013; η p 2 = 0.41; ES = 0.83) and CMJAp (F1,12 = 7.69; p = 0.017; η p 2 = 0.39; ES = 0.79). This study reveals that performance related to the counter movement jump with arms on softer surfaces after 4-week plyometric training improved vertical jump displacement and lower body power in rugby sevens players.
ABSTRACT
Resumen Lagos-Hernández, R.I. et al. (2018). Perfil antropométrico e imagen corporal de escolares rugbistas de sexo femenino de la región de la Araucanía, Chile. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-15. El objetivo de esta investigación fue determinar perfil antropométrico y su relación con el IMC e imagen corporal (IC) del total de escolares de sexo femenino de la Región de la Araucanía, Chile, que practican regular y competitivamente rugby 7. En relación a las participantes, se evaluaron 25 niñas que reunían los criterios de inclusión cuyas edades fluctuaron entre los 10 y 19 años (Media = 16.39 ± 2.81). Para efectos metodológicos se llevó a cabo una evaluación Antropométrica bajo los protocolos de la International Society for the Advancement of Kinanthropometry protocols (ISAK , 2017) y se hizo una apreciación de la percepción de la IC a través de la observación de una serie de imágenes corporales siguiendo el protocolo de Montero, Morales, & Carbajal (2004). Los resultados mostraron que las escolares evaluadas presentan una composición corporal (CC) alta en tejido adiposo con un 33.9% y un porcentaje muscular de 39%. En relación a la clasificación antropomética, se puede señalar que manifiestan características endo-mesomorficas, además se pudo constatar que las escolares presentaron una percepción de la IC según IMC percibido, diferente de los niveles reales de IMC presentados, no apreciándose relacion estadísticamente significativa entre la CC, el somatotipo y la imagen percibida.
Abstract Lagos-Hernández, R.I. et al. (2018). Anthropometric profile and body image of female junior Rugby players from the Region of Araucanía, Chile. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-15. The objective of this paper was to determine the anthropometric profile of female students of the Region of Araucanía, Chile, and its relationship with BMI (IMCA) and body image (IC). Participants included 25 girls ages 10 to 19 (mean = 16.39 ± 2.81) that practice rugby sevens on a regular and competitive basis. For methodological purposes, an anthropometric assessment was conducted using the International Society for the Advancement of Kinanthropometry protocols (ISAK, 2017), and an appreciation of CI perception was made by observing a series of body images following the Montero, Morales, & Carbajal protocol (2004). Results showed that the students' body composition (CC) was high in adipose tissue (33.9%) and their muscle percentage was 39%. Regarding the anthropometric classification, it can be noted that participants show endo-mesomorph characteristics and that their perceived body image differed from the actual BMI levels, not showing a statistically significant relationship between the body composition, the somatotype and the perceived image.
Resumo Lagos-Hernández, R.I. et al. (2018). Perfil antropométrico e imagem corporal de escolares do sexo feminino jogadoras de rugby da região de Araucanía, Chile. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-15. O objetivo desta pesquisa foi determinar o perfil antropométrico e sua relação com o IMC e a imagem corporal (IC) de todas as escolares da região de Araucania, Chile, que praticam regularmente o rugby 7 em carácter competitivo. Em relação aos participantes, foram avaliadas 25 meninas que atendiam aos critérios de inclusão cujas idades variaram entre 10 e 19 anos (média = 16,39 ± 2,81). Para fins metodológicos, foi levada a cabo uma avaliação antropométrica sob os protocolos da Society for Avancement in Kineanthropometric (ISAK, 2017) e feita uma apreciação da percepção do IC através da observação de uma série de imagens corporais seguindo o protocolo de Montero, Morales e Carbajal (2004). Os resultados mostraram que as estudantes avaliadas apresentam uma composição corporal (CC) elevada no tecido adiposo com 33,9% e um percentual muscular de 39%. Quanto à classificação antropométrica, pode-se destacar que se manifestam características endo-mesomórficas e, além disso, verificou-se que as escolares apresentaram uma percepção de IC de acordo com o IMC percebido, diferente dos níveis reais de IMC apresentados, não sendo apreciada uma relação estatisticamente significativa entre a CC, o somatótipo e a imagem percebida.
