The use of creatine monohydrate (Cr) in professional soccer is widely documented. However, the effect of low doses of Cr on the physical performance of young soccer players is unknown. This study determined the effect of a low dose of orally administered Cr on muscle power after acute intra-session fatigue in young soccer players. Twenty-eight young soccer players (mean age = 17.1 ± 0.9 years) were randomly assigned to either a Cr (n = 14, 0.3 g·kg⁻¹·day⁻¹ for 14 days) or placebo group (n = 14), using a two-group matched, double-blind, placebo-controlled design. Before and after supplementation, participants performed 21 repetitions of 30 m (fatigue induction), and then, to measure muscle power, they performed four repetitions in half back squat (HBS) at 65% of 1RM. Statistical analysis included a two-factor ANOVA (p ˂ 0.05). Bar velocity at HBS, time: p = 0.0006, ${\mathrm{ŋ}}_{\mathrm{p}}^2$ = 0.22; group: p = 0.0431, ${\mathrm{ŋ}}_{\mathrm{p}}^2$ = 0.12, time × group p = 0.0744, ${\mathrm{ŋ}}_{\mathrm{p}}^2$ = 0.02. Power at HBS, time: p = 0.0006, ${\mathrm{ŋ}}_{\mathrm{p}}^2$ = 0.12; group: p = 0.16, ${\mathrm{ŋ}}_{\mathrm{p}}^2$ = 0.06, time × group: p = 0.17, ${\mathrm{ŋ}}_{\mathrm{p}}^2$ = 0.009. At the end of the study, it was found that, after the induction of acute intra-session fatigue, a low dose of Cr administered orally increases muscle power in young soccer players.

To determine the acute effect of low and high-dose BA trials on maximal aerobic speed (MAS) in endurance athletes. We hypothesized that high doses of BA have a greater effect than low doses, both c...

Diversas investigaciones han determinado que la implementación de programas de actividad física mejora la salud mental. Sin embargo, aún existen dudas sobre los beneficios de los programas Zumba® en la población que lo practica. El propósito de este estudio fue determinar los efectos de un programa de ejercicio físico basado en Zumba®, sobre los niveles de ansiedad-rasgo y ansiedad-estado en estudiantes universitarias chilenas. Investigación cuantitativa cuasi-experimental, con una muestra de 22 estudiantes mujeres de pregrado (grupo experimental = 10 y grupo control = 12). Las variables fueron: ansiedad-rasgo (A-R) y ansiedad-estado (A-E), además de variables físicas como antropometría, consumo máximo de oxígeno (VO2máx) y fuerza prensil. El análisis estadístico se realizó a través de un ANOVA mixto para todas las variables. En nivel de significancia fue de p < 0,05. Los resultados evidenciaron cambios no significativos en los distintos niveles de A-R ni A-E luego de la aplicación del programa de Zumba® (p > 0,05), tampoco hubo cambios en las otras variables de estudio (p > 0,05). Al término de la intervención, no se observaron efectos del programa de Zumba® sobre los distintos niveles de A-R y A-E, como tampoco sobre variables antropométricas, VO2máx ni fuerza prensil. Several investigations have specified that the implementation of physical activity programs improve mental health. However, there are still doubts about the benefits on the population taking part in Zumba® programs. The purpose of this study was to determine the effects of a Zumba® based working out program on the levels of anxiety-trait and anxiety-state in Chilean university students. It was a quantitative, cuasi-experimental study with a sample of 22 undergraduate female students (experimental group = 10 and control group = 12). The variables were anxiety-trait (A-T) and anxiety-state (A-S), in addition to physical variables, such as anthropometry, maximum oxygen consumption (VO2max) and grip strength. A statistical analysis was performed through a mixed ANOVA. The level of significance for all analyses was p < 0.05. The results showed no significant changes in the different levels of A-T or A-S (p > 0.05), there were also no changes in the other variables (p > 0.05). At the end of the intervention, no effects of the Zumba® program were observed on the different levels of A-T and A-S, nor on anthropometric variables, VO2max or grip strength. Várias investigações determinaram que a implementação de programas de atividade física melhora a saúde mental. No entanto, ainda existem dúvidas sobre os benefícios dos programas Zumba® na população que pratica. O objetivo deste estudo foi determinar os efeitos de um programa de exercícios físicos baseado no Zumba®, sobre níveis de Ansiedade-Traço e Ansiedade-Estado em estudantes universitários chilenos. Pesquisa quantitativa quase experimental, com uma amostra de 22 estudantes do sexo feminino (grupo experimental [GE] = 10 e grupo controle [GC] = 12). As variáveis foram: Ansiedade-Traço (A-T) e Ansiedade-Estado (A-E), ambas avaliadas pelo STAI Trait State Anxiety Questionnaire, além de variáveis físicas como antropometria, consumo máximo de oxigênio (VO2máx) e força pré-trilateral. A análise estatística foi realizada através de uma ANOVA mista para todas as variáveis e uma tabela de contingência por meio do Qui-Quadrado de Pearson para os diferentes níveis de A-T e A-E. O nível de significância para todas as análises foi de p 0,05); também não houve diferenças nos diferentes níveis de A-T ou A-E (p> 0,05). Ao final da intervenção, não foram observados efeitos do programa Zumba® sobre diferentes níveis de A-R e A-E, nem nas variáveis antropométricas, VO2máx ou força preênsil.

The objectives of this study were: (a) to determine asymmetries, both lower limb (LL) and upper limb (UL), in Chilean older adults, and (b) to relate asymmetries to FA in both LL and UL. Forty-one older adults voluntarily participated in this study (mean ± standard deviation [SD]: age 72.0 ± 8.0 years, LL asymmetries 13.78 ± 14.87%, UL asymmetries 10.70 ± 8.85%, FA 40.35 ± 16.26 points). The variables were: (1) asymmetries of LL and UL, assessed through a force platform and handgrip, respectively; (2) FA, assessed through the Latin American Group for Maturity (GDLAM) and the GDLAM index of autonomy (GI) protocol. The relationship between the variables was performed through Spearman’s correlation. The analysis showed that 39% of the participants presented asymmetries above 15% in the LL. Likewise, this 39% of older adults presented a lower FA than their peers with asymmetries below 15% in the LL (≤15%: 35.64 ± 12.26 points vs. >15%: 47.69 ± 19.23 points, p = 0.003). The analysis showed a small correlation between LL and GI asymmetries (r = 0.27, p = 0.07) and a small but negative correlation between UL and GI (r = −0.21). The mean values of asymmetries of both LL and UL are within ‘normal’ parameters. However, several older adults were identified as being at risk. In parallel, older adults who presented a higher level of asymmetries in LL showed a lower level of FA.

Introduction: Block strength training has been proposed as a useful and practical strategy to reverse the effects of aging in community-dwelling older adults. However, the effects of block strength training based on the nature of exertion on functional autonomy and life quality of older women living in the community are unknown. Objective: To determine the effects of a Block Strength Training program based on the level of effort on functional autonomy and self-perceived life quality in community-dwelling older women. Methodology: Eighteen older women (71.1 ± 8.01 years) residing in the community volunteered for the study. The study had a pre-experimental design with pre- and post-tests. The block strength training is 12 weeks and divided into three blocks of 4 weeks each. The study variables were functional autonomy, assessed with the GDLAM protocol, and self-perceived life quality, assessed with WHOQOL-BREF. Differences between pre- and post-intervention were performed using t-tests and Wilcoxon tests, both for related samples (p < 0.05). Results: After applying the 12-week block strength training, 4 of the five tests of the GDLAM protocol showed significant improvements (p < 0.05). Likewise, 2 of the four dimensions of the WHOQOL-Bref showed significant improvements (p < 0.05). Conclusions: A Block Strength Training program based on the level of effort significantly improves functional autonomy and self-perceived life quality in older women community residents. Consequently, this methodology is effective and practical for promoting healthy aging in the community.

Introducción: Los bajos niveles de Consumo Máximo de Oxígeno (VO2max) evaluados en escolares chilenos, sugieren la puesta en marcha de entrenamientos que mejoren la capacidad aeróbica. Objetivo: Analizar el efecto de un método de Entrenamiento Intervalado de Alta Intensidad sobre el Consumo Máximo de Oxígeno en escolares chilenos. Materiales y métodos: Treinta y dos escolares de octavo año básico divididos en dos grupos fueron parte del estudio (grupo experimental = 16 y grupo control = 16). La principal variable analizada fue el Consumo Máximo de Oxígeno a través del Test de Course Navette. Se aplicó un método de Entrenamiento Intervalado de Alta Intensidad basado en la Velocidad Aeróbica Máxima obtenida a través del Test. Para el análisis estadístico se utilizó un ANOVA Mixto. Resultados: El grupo experimental presentó un aumento significativo en el Consumo Máximo de Oxígeno entre el pre test y post test al ser comparado con el grupo control (p < 0.0001). Conclusión: Los resultados del estudio mostraron un efecto positivo del Entrenamiento Intervalado de Alta Intensidad sobre el Consumo Máximo de Oxígeno. Al término del estudio, se concluye que el Entrenamiento Intervalado de Alta Intensidad es una buena metodología de estimulación para escolares chilenos.