ABSTRACT
OBJECTIVES: The aim of this study was to evaluate the effects of 8 weeks of strength training (ST) combined with whole-body electrical stimulation (EMS) on morphofunctional adaptations in active individuals. METHODS: Fifty-eight volunteers were randomly distributed into the following groups: an untrained control (UN) group (n=16), an ST group (n=21) or an ST combined with EMS (ST+EMS) group (n=21). Both intervention groups (the ST and ST+EMS groups) performed 3 exercises (biceps curl, back squats and high-pulley tricep extensions) twice a week for 8 weeks. The subjects performed 3 sets of 8 to 12 maximum repetitions (MRs) with a 90-second rest duration between sets. The ST+EMS group performed the resistance training exercises wearing a whole-body suit that provided electrical stimulation at frequencies between 80-85 Hz, with a continuously bipolar impulse duration and pulse breadth of 350 µs. The intensity for each muscle group was controlled by Borg's category ratio (CR)-10 scale; the intensity started at 5-6 and eventually reached 7-8. One-repetition maximum strength (1RM) and muscle thickness (MT) were measured before and after the training intervention. MT was evaluated in the biceps brachii (BB), triceps brachii (TB), and vastus lateralis (VL). RESULTS: No differences (p>0.05) were found between the ST and ST+EMS groups. Improvements (p<0.05) in the absolute values of the morphofunctional parameters after the training protocol were observed. Significant differences were found between both the intervention groups and the UN group (p<0.05). The ST+EMS group presented high percentage changes (p<0.05) in muscular strength for the 1RMsquat (43.2%, ES=1.64) and the MT of the BB (21.6%, ES=1.21) compared to the ST (20.5%, ES=1.43, 11.9%, ES=0.77) group. CONCLUSIONS: Our data suggest that the combination of ST+EMS may promote alterations in muscle strength and MT in healthy active subjects.
Subject(s)
Humans , Male , Adult , Young Adult , Muscle, Skeletal/physiology , Electric Stimulation/methods , Muscle Strength/physiology , Resistance Training/methods , Random AllocationABSTRACT
Os efeitos da vibração sobre o corpo humano são documentados há muitos anos. Recentemente, o uso da vibração tem se destacado como método auxiliar no treinamento das capacidades físicas de indivíduos jovens, atletas e idosos. Estudos recentes indicam aumento no ganho de força, flexibilidade, resistência e potência de indivíduos treinados com equipamentos vibratórios, porém, os efeitos fisiológicos da vibração ainda são pouco entendidos, além de existir uma grande variedade dos protocolos de treinamento usados na literatura científica. A vibração apresenta-se como um importante estímulo ao sistema neuromuscular, entretanto, futuros estudos devem ser realizados como forma de se entender melhor os efeitos fisiológicos da vibração, bem como os efeitos de diferentes protocolos sobre o treinamento de capacidades físicas como força, flexibilidade, resistência e potência.
The effects of vibration on the human body have been documented for many years. Recently, the use of vibration is an auxiliary method of physical training in the young, elderly and athletes. Recent studies indicate an increase in gain of strength, flexibility, endurance and power of individuals trained with vibrating equipments. Despite the fairly widespread use, the physiological effects of vibration are still poorly understood, and there is great variability in the training protocols used in the literature. Future studies should be conducted as a way to better understand the physiological effects of vibration and also the affects of different protocols on physical training as strength, flexibility, endurance and power.
Subject(s)
Physical Education and Training , Physical Fitness , VibrationABSTRACT
Los objetivos de este trabajo fueron calcular el índice de prevalencia de alteraciones posturales en una muestra de 120 alumnos (10,4 por ciento del universo total), de 4 años de edad de la ciudad de Arica y determinar el efecto de un programa de mejoramiento postural. Las alteraciones posturales más frecuentes corresponden a: inclinación de hombros (86 por ciento), escápula alada y escápula descendida (82 por ciento), proyección anterior de hombros (79 por ciento), pie plano (58 por ciento), columna lumbar hiperlordótica (51 por ciento) e inclinación de cabeza (50 por ciento). Posteriormente, se aplicó al grupo experimental un programa de ejercicio muscular y de reeducación postural, por un período de 8 meses. Al final del tratamiento se realizó un análisis post test a todos los sujetos del estudio. Los resultados en el grupo experimental muestran una disminución significativa de los índices iniciales de prevalencia, en todas las alteraciones en estudio. Los diferenciales de recuperación muestran diferencias significativas entre los grupos de estudio, con un 31 por ciento para inclinación de hombros, seguida de hiperlordosis lumbar con un 29 por ciento e inclinación de cabeza con 20 por ciento. La recuperabilidad más baja se observó en pie plano con un 7 por ciento (p≤0,05). El alto porcentaje de alteraciones posturales presentes en niños de 4 años, de la ciudad de Arica, podría ser producto de actitudes viciosas que, a futuro producen una estructuración inadecuada del cuerpo, entonces la aplicación de un programa de ejercitación muscular y de reeducación postural, dirigido por un equipo de Salud multiprofesional disminuirían significativamente estas alteraciones.
At present the educational institutions do not have an adequate system of Health to detect early changes in postural alteration in children. The aim of this study was to determine the most common postural changes in a sample of 120 students (10,4 percent of total universe), of 4 years old from Arica-Chile and to determine the effect of a program to improve the posture. The prevalence of the most frequent postural alterations relate to: inclination of shoulders (86 percent), winged scapula and descend scapula (82 percent), projection front shoulders (79 percent), flat feet (58 percent), lumbar hyperlordosis (51 percent) and inclination of head (50 percent). Subsequently in the experimental group was applied a program of exercise muscle and postural reeducation for a period of 8 months. At the end of treatment was applied a post-test to all children. The results in the experimental group showed a significant decrease in initial prevalence rates in all alterations. The differential recovery shows significant differences among the study groups, with 31 percent for inclination of shoulders, followed by lumbar hyperlordosis (29 percent) and inclination of head (20 percent). The recoverability lowest level was observed in flat feet with 7 percent (p≤0,05).The high percentage of postural disturbances in children aged 4 years in the city of Arica, could be the result of vicious attitudes that in the future produce an improper structuring of the body. Then the implementation of a program of exercise muscles and postural reeducation, led by a multiprofesional health team, decline rates of postural abnormalities present in children.