Energy expenditure in hiit whole body associated with electromyostimulation / Gasto energético en hiit con peso corporal asociado a electroestimulación / Gasto energético no hiit com peso do corpo associado à eletromioestimulação

ABSTRACT Introduction: The use of whole body electromyostimulation (WB-EMS) has been shown to be an efficient method for inducing significant improvements in muscle strength and performance outcomes. Hypothetically, WB-EMS had been considered an enhancer of energy expenditure in the session, but this remains unclear. Objective: In view of the lack of information, this study aims to evaluate the energy expenditure of WB-EMS associated with whole body High-Intensity Interval Training (HIIT). Methods: Fourteen male participants were submitted into two randomized exercise sessions: HIIT (whole body weight exercises without WB-EMS) and HIIT+WB-EMS (whole body weight exercises associated with WB-EMS). For both exercise conditions, the subjects performed whole body HIIT according to the following protocol: 3 minutes of warm-up followed by 4 exercises (30 seconds of stimulus) organized in 2 blocks, with 3 sets in each exercise, a rest period of 15 seconds between sets, and 180 seconds between blocks. The following exercises were performed: jumping jacks, squat and thrusts, burpees, and spider plank. Results: Significant differences were found in the absolute VO2 (HIIT:2.18±0.34, HIIT+WB-EMS:2.32±0.36 L.min−1) and relative VO2 (HIIT:26.30±3.77, HIIT+WB-EMS:28.02± 3.74 ml.kg.min−1), MET (HIIT:7.51±1.07, HIIT+WB-EMS:8.00±1.07), lactate concentration (HIIT:11.59±2.16, HIIT+WB-EMS: 12.64±1.99 mmol.L−1) and total energy expenditure (HIIT: 249.6± 45.04 Kcal, HIIT+ WB-EMS: 268.9±40.67 Kcal; 7.46 ± 5.31%). Conclusion: Our data indicate that the use of WB-EMS associated with HIIT generated a slightly higher metabolic demand than that of the control. However, the absolute differences do not allow us to indicate the superiority of WB-EMS, and future trials should be designed to determine the long-term effects.

RESUMEN Introducción: Se ha demostrado que el uso de la electroestimulación de cuerpo entero (WB-EMS) es un método eficaz para inducir mejoras significativas en la fuerza muscular y los resultados de rendimiento. Hipotéticamente, la práctica de WB-EMS se consideró un potenciador del gasto calórico en la sesión, pero esto aún no está claro. Objetivo: el objetivo del estudio fue evaluar el gasto energético del WB-EMS asociado al HIIT con el peso corporal. Métodos: Se asignaron al azar catorce participantes masculinos a dos sesiones de ejercicio: HIIT (ejercicios de peso corporal total sin WB-EMS) y HIIT + WB-EMS (ejercicios de peso corporal total asociados con WB-EMS). Para ambas condiciones de ejercicio, los sujetos realizaron HIIT con peso corporal según el siguiente protocolo: 3 minutos de calentamiento seguido de 4 ejercicios (30 segundos de estímulo) organizados en 2 bloques con 3 series en cada ejercicio y 15 segundos entre series y ejercicios y 180 segundos entre bloques de descanso pasivo con los siguientes ejercicios realizados: jump jack, squat and thrust, burpee y spider plank. Resultados: Se encontraron diferencias significativas en el consumo de VO2 absoluto (HIIT: 2,18 ± 0,34, HIIT + WB-EMS: 2,32 ± 0,36 L.min−1) y relativo (HIIT: 26,30 ± 3,77, HIIT + WB-EMS: 28,02 ± 3,74 ml.kg.min1), MET (HIIT: 7,51 ± 1,07, HIIT + WB-EMS: 8,00 ± 1, 07), concentración de lactato (HIIT: 11,59 ± 2,16, HIIT + WB-EMS: 12,64 ± 1,99 mmol.L−1) y gasto energetico total (HIIT: 231,5±36,38Kcal, HIIT + WB-EMS:246,9± 38,76Kcal; 6,14± 5,61%). Conclusión: Nuestros datos indican que el uso de WB-EMS asociado a HIIT generó, en una de manera sutil, una mayor respuesta a la demanda metabólica que la situación de control. Sin embargo, las diferencias absolutas no permiten indicar la superioridad del WB-EMS con estudios futuros y deben planificarse.

RESUMO Introdução: O uso da eletromioestimulação de corpo inteiro (whole body electromyostimulation - WB-EMS) tem mostrado ser um método eficiente para induzir melhora significativa da força muscular e do desempenho. Hipoteticamente, a prática de WB-EMS foi considerada potencializadora do gasto energético na sessão, mas isso ainda não está claro. Objetivo: Diante da escassez de informações, o objetivo deste estudo foi avaliar o gasto energético da WB-EMS associada ao treinamento intervalado de alta intensidade (HIIT) com o peso corporal. Métodos: Quatorze participantes do sexo masculino foram submetidos a duas sessões de exercícios randomizadas: HIIT (exercícios com peso corporal sem WB-EMS) e HIIT + WB-EMS (exercícios com peso corporal associados a WB-EMS). Para ambas as condições de exercício, os indivíduos realizaram HIIT com peso corporal, de acordo com o seguinte protocolo: 3 minutos de aquecimento seguidos de 4 exercícios (30 segundos de estímulo), organizados em 2 blocos com 3 séries em cada exercício, com 15 segundos de descanso passivo entre as séries e 180 segundos entre os blocos, com os seguintes exercícios realizados: jumping jack (polichinelo), squat and thrust, burpee e spider plank. Resultados: Diferenças significativas foram encontradas no consumo de VO2 absoluto (HIIT: 2,18 ± 0,34, HIIT + WB-EMS: 2,32 ± 0,36; L.min−1) e VO2 relativo (HIIT: 26,30 ± 3,77, HIIT + WB-EMS: 28,02 ± 3,74; ml.kg.min−1), MET (HIIT: 7,51 ± 1,07, HIIT + WB-EMS: 8,00 ± 1,07), concentração no sangue de lactato (HIIT: 11,59 ± 2,16, HIIT + WB- EMS: 12,64 ± 1,99 mmol.L−1) e gasto energético total (HIIT: 249,6± 45,04 Kcal, HIIT+ WB-EMS: 268,9± 40,67 Kcal; 7,46 ± 5,31%). Conclusão: Nossos dados indicam que o uso de WB-EMS associado ao HIIT gerou demanda metabólica ligeiramente superior à do controle. Entretanto, as diferenças absolutas não permitem indicar superioridade do WB-EMS, e estudos futuros devem ser planejados de modo a determinar os efeitos a longo prazo. Nível de evidência II.

Does whole-body electrical muscle stimulation combined with strength training promote morphofunctional alterations?

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.

Does whole-body electrical muscle stimulation combined with strength training promote morphofunctional alterations?

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.