Exercise-Induced Muscle Damage after a High-Intensity Interval Exercise Session: Systematic Review.

High-intensity interval training (HIIT) is considered an effective method to improve fitness and health indicators, but its high-intensity exercises and the mechanical and metabolic stress generated during the session can lead to the occurrence of exercise-induced muscle damage. Therefore, this study aimed to describe, by means of a systematic review, the effects of a single HIIT session on exercise-induced muscle damage. A total of 43 studies were found in the Medline/PubMed Science Direct/Embase/Scielo/CINAHL/LILACS databases; however, after applying the exclusion criteria, only 15 articles were considered eligible for this review. The total sample was 315 participants. Among them, 77.2% were men, 13.3% were women and 9.5 uninformed. Their age ranged from 20.1 ± 2 to 47.8 ± 7.5 years. HIIT protocols included running with ergometers (n = 6), CrossFit-specific exercises (n = 2), running without ergometers (n = 3), swimming (n = 1), the Wingate test on stationary bicycles (n = 2), and cycling (n = 1). The most applied intensity controls were %vVO2max, "all out", MV, MAV, Vmax, and HRreserve%. The most used markers to evaluate muscle damage were creatine kinase, myoglobin, and lactate dehydrogenase. The time for muscle damage assessment ranged from immediately post exercise to seven days. HIIT protocols were able to promote changes in markers of exercise-induced muscle damage, evidenced by increases in CK, Mb, LDH, AST, ALT, pain, and muscle circumference observed mainly immediately and 24 h after the HIIT session.

Corrigendum: Position statement and updated international guideline for safe and effective whole-body electromyostimulation training-the need for common sense in WB-EMS application.

[This corrects the article DOI: 10.3389/fphys.2023.1174103.].

Position statement and updated international guideline for safe and effective whole-body electromyostimulation training-the need for common sense in WB-EMS application.

Whole-Body Electromyostimulation (WB-EMS) is a training technology that enables simultaneous stimulation of all the main muscle groups with a specific impulse intensity for each electrode. The corresponding time-efficiency and joint-friendliness of WB-EMS may be particularly attractive for people unable or unmotivated to conduct (intense) conventional training protocols. However, due to the enormous metabolic and musculoskeletal impact of WB-EMS, particular attention must be paid to the application of this technology. In the past, several scientific and newspaper articles reported severe adverse effects of WB-EMS. To increase the safety of commercial non-medical WB-EMS application, recommendations "for safe and effective whole-body electromyostimulation" were launched in 2016. However, new developments and trends require an update of these recommendations to incorporate more international expertise with demonstrated experience in the application of WB-EMS. The new version of these consensus-based recommendations has been structured into 1) "general aspects of WB-EMS", 2) "preparation for training", recommendations for the 3) "WB-EMS application" itself and 4) "safety aspects during and after training". Key topics particularly addressed are 1) consistent and close supervision of WB-EMS application, 2) mandatory qualification of WB-EMS trainers, 3) anamnesis and corresponding consideration of contraindications prior to WB-EMS, 4) the participant's proper preparation for the session, 5) careful preparation of the WB-EMS novice, 6) appropriate regeneration periods between WB-EMS sessions and 7) continuous interaction between trainer and participant at a close physical distance. In summary, we are convinced that the present guideline will contribute to greater safety and effectiveness in the area of non-medical commercial WB-EMS application.

Psychophysiological Responses of Exercise Distribution During High Intensity Interval Training Using Whole Body Exercise.

The time-efficient nature of HIIT using bodyweight exercises can facilitate the application of exercise programs at home by encouraging more people to perform regular physical exercise. However, there are no studies investigating the influence of the distribution/order of exercises during HIIT training sessions using this method. The aim of the present study was to evaluate the effects of different exercise orders on training load indicators during HIIT sessions using body weight. Twenty male participants performed three 20-min sessions of HIIT using whole body exercise, consisting of 20 sets with 30 s of activity performed at maximal intensity, followed by 30 s of passive recovery. Three designs of exercise protocols were randomly performed according to the following exercise distribution: A: jumping jack, burpee, mountain climb and squat jump); B: jumping jack, mountain climb, burpee, and squat jump) and C: burpee, squat jump, jumping jack and mountain climb. No differences were found between protocols for relative heart rate, perceived exertion, and lactate concentrations. Significant differences (p < 0.001) were found for the number of movements (A:712 ± 59, B:524 ± 49, C:452 ± 65). No differences were observed for the area under curve when examining perceived exertion between protocols. However, the values for perceived recovery significantly differed (p < 0.001) between protocols (A:64 ± 19; B:52 ± 11; C:17 ± 13). Interestingly, protocol B and C induced a displeasure perception compared to protocol A. Our findings suggest that exercise distribution/order using HIIT whole body exercise promotes alterations in psychophysiological responses in HIIT using whole body exercises.

Effects of music on psychophysiological responses during high intensity interval training using body weight exercises.

The use of music in exercise sessions is considered an interesting strategy as it facilitates, through motivation, an improvement in physical performance, as well as a reduction in the subjective perception of effort and an improvement in mood. Such factors are important for the maintenance of physical exercise programs, however, considering high intensity interval training, the effects of music remain inconclusive. Thus, the objective of this study was to evaluate the influence of music during high intensity interval training sessions using body weight (HIIT-B) on the physiological parameters and mood state of adults. METHODS: 11 CrossFit male practitioners were randomly submitted to three sessions of HIIT-B under the following experimental conditions: preference music (PM), non-preference music (nPM) and without music (WM). The HIIT-B protocol consisted of 20 sets of 30 s of stimulus using maximal intensities followed by 30 s of passive recovery. The following exercises were used: jumping jacks, burpee, mountain climber and squat jumping. The following parameters were analyzed: heart rate (HR), lactate (La), total amount of movements (TAM), affective response (AR), rating of perceived exertion (RPE), recovery (RPR) and mood states. RESULTS: although an increase (p< 0.05) of HR, RPE and La, reduction of RPR was found after performing the HIIT session, no differences were found between the three conditions to these parameters. The nPM condition promoted lower (p< 0.001) TAM compared to the WM and PM conditions, which also differed from each other. However, for AR, a music effect was found among the protocols (p< 0.0001), indicating that the PM session promoted an increase in pleasure, unlike WM and nPM session which provided pleasure reduction and displeasure respectively. The WM session did not promote any changes. There were no main effects on time for depression and anger, which were different for vigor, fatigue, mental confusion, tension and mood disturbance. Additionally, differences were found after session to tension (p = 0.0229), vigor (p = 0.0424) and fatigue (p = 0.0400) for PM condition, vigor (p = 0.0424), fatigue (p = 0.0400) mental confusion (p = 0.0302) and mood disturbance (p = 0.0129) for nPM and vigor (p = 0.0363) and fatigue (p = 0.0468) to WM conditions. CONCLUSION: Listening to preferred music during an 'all out' HIIT-B session increases exercise performance and elicits more positive affective responses in recreationally active adult males, despite similar HR, blood lactate, RPE and fatigue compared to nonpreferred music or no-music.

Effect of a short-term whole-body high-intensity interval training on fitness, morphological, and functional parameters in untrained individuals.

BACKGROUND: High-intensity interval training protocols using the body weight (WB-HIIT) as resistance could be an interesting and inexpensive alternative due to the absence of equipment required (low cost) and the possibility to be performed in a wide range of locations. Therefore, the purpose of the present study was to analyze the effects of a short-term WB-HIIT protocol on muscle thickness (MT), muscular endurance (ME), one maximum repetition test (1RM), and maximum oxygen uptake (VO2max) of untrained individuals. METHODS: Fifty healthy men (28.2±6.7 years, 77.5±26.2 kg, 171±10 cm, 23.2±8.2% Fat) were randomized into WB-HIIT (N.=25) or control (CON, N.=25) group. The WB-HIIT performed 9 exercises (40-second stimulus in all out intensity/ 20-second of passive recovery) divided into 3 blocks with 2 sets each for 6 weeks (three times a week). RESULTS: Only WB-HIIT resulted in a significant increase in MT, ME, 1RM, and VO2max (all P<0.05) outcomes and were significantly greater compared to CON (all P<0.05). CONCLUSIONS: Our results demonstrate that a WB-HIIT program can be a time-efficient strategy to promote changes on fitness, morphological and functional parameters in previously untrained sedentary individuals.

Loaded Inter-set Stretching for Muscular Adaptations in Trained Males: Is the Hype Real?

The study examined the effects of adding a loaded stretch in the inter-set rest period (ISS) compared to traditional resistance training (TR) on muscular adaptations in resistance-trained males. Twenty-six subjects were randomly assigned into two groups (ISS: n=12; TR: n=14) and underwent an 8-week training regimen. Subjects in ISS underwent an additional loaded stretch for 30 s at 15% of their working load from the prior set during the inter-set rest periods. Muscle thickness of the pectoralis major at the belly (BMT) and lateral (LMT) portions, One-repetition maximum (1RM) and repetitions-to-failure (RTF) on the bench press exercise were measured at baseline and post 8 weeks of training. Additionally, volume load and perceptual parameters for exertion and recovery were measured. Both groups had similar total volume load and average perceptual parameters (p>0.05). There was a main time effect (p<0.01) for all but one dependent variable indicating that both groups responded similarly across time [(∆BMT: ISS=2.7±1.7 mm; TR = 3.0±2.2 mm), (∆LMT: ISS=3.2±1.6 mm; TR=2.8±1.7 mm, (∆1RM: ISS=6.6±3.8 kg; TR=7.5±5.7 kg). Repetitions-to-failure did not change in either group (∆RTF: ISS=0.0±2.1 repetitions; TR=0.0±2.3 repetitions, p>0.05). Our results suggest that addition of a loaded ISS does not affect muscular adaptations either positively or negatively in resistance-trained males.

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.

Split or full-body workout routine: which is best to increase muscle strength and hypertrophy?

OBJECTIVE: To compare the effects of different resistance training programs on measures of muscle strength and hypertrophy. METHODS: Sixty-seven untrained subjects were randomized to one of two groups: Split Workout Routine (n=35), in which muscle groups were trained twice per week in an A/B split consisting of eight sets per session, or Full-Body Workout Routine (n=32), in which muscle groups were trained four times per week with four and eight sets per session. Both groups performed eight to 12 repetition maximum per set, with 60 seconds of rest between sets. Maximal strength and muscle thickness were assessed at baseline and after eight weeks of training. RESULTS: A significant main effect of time (pre versus post) was observed for maximal strength in the bench press and squat exercises and thickness of the elbow extensor, elbow flexor and quadriceps femoris muscles. Selected variables did not differ significantly between groups. CONCLUSION: Resistance training twice or four times per week has similar effects on neuromuscular adaptation, provided weekly set volume is equal.

Corrigendum: Effects of Whole Body Electrostimulation Associated With Body Weight Training on Functional Capacity and Body Composition in Inactive Older People.

[This corrects the article DOI: 10.3389/fphys.2021.638936.].

Corrigendum: Effects of Whole Body Electrostimulation Associated With Body Weight Training on Functional Capacity and Body Composition in Inactive Older People.

[This corrects the article DOI: 10.3389/fphys.2021.638936.].

Effects of Whole Body Electrostimulation Associated With Body Weight Training on Functional Capacity and Body Composition in Inactive Older People.

Objective: To analyze the effects of whole body electrostimulation (WB-EMS) with body weight training on functional fitness and body composition of older men. Methods: Twenty physically inactive older men were randomized into: Control group (control), performed the body weight exercise training wearing electrostimulation clothing, but without receiving electrical current stimuli (n = 10), and body weight associated with whole body electrostimulation group (BW+WB-EMS), performed the body weight exercise training wearing electrostimulation clothing plus whole body electrostimulation (n = 10). The training sessions were performed twice a week for 6 weeks and included eight exercises using body weight, performed in two sets of eight repetitions. Physical function was assessed using a battery composed of seven tests, six derived from the Senior fitness test and a handgrip strength test. We also measured the muscle thickness (MT) of the biceps and triceps brachii and vastus lateralis. Results: The BW+WB-EMS group presented increased (p < 0.05) performance in the 30-s chair stand test (10.2 ± 3.3 vs. 13.8 ± 5.0 reps), arm curl (16.6 ± 3.9 vs. 19.9 ± 6.1 reps), 6-min walk test (402 ± 96 vs. 500 ± 104 m), and handgrip strength test (30 ± 11 vs. 32 ± 11 kgf). The BW+WB-EMS group also presented increased MT (p < 0.05) in the biceps brachii (17.7 ± 3.0 vs. 21.4 ± 3.4 mm), triceps brachial (14.7 ± 3.6 vs. 17.5 ± 4.1 mm), and vastus lateralis muscles (15.1 ± 2.6 vs. 18.6 ± 4.3 mm). Moderate correlations were found in arm curl (p = 0.011, r = 0.552) but not handgrip strength (p = 0.053, r = 0.439) with changes in the biceps MT. Moderate changes in the 6-min walk distance were significantly correlated with changes in vastus lateralis MT (p = 0.036, r = 0.471). There was a moderate correlation between the changes in the 30-s chair stand test (p = 0.006, r = 0.589) and changes in the vastus lateralis MT. Furthermore, although a moderate correlation (r = 0.438) was found between triceps MT and handgrip strength no significant difference (p = 0.053) was reported. Additionally, there were no statistical differences in any parameters for the control group. Conclusion: WB-EMS with body weight training increased functional fitness and MT in physically inactive older men.

The dose-response phenomenon associated with strength training is independent of the volume of sets and repetitions per session / O fenômeno de dose-resposta associado ao treinamento de força é independente do volume de séries e repetições por sessão / El fenómeno de dosis-respuesta asociado al entrenamiento de fuerza es independiente del volumen de series y repeticiones por sesión

ABSTRACT Introduction There are few studies on the effectiveness of training models with high volume sets per session in particular muscle groups. Objective The aim of the study was to investigate the effects of different resistance training (RT) repetitions with equalized volumes on muscle adaptations. Methods This study used an experimental design in which forty-seven volunteers underwent 8 weeks of RT after having been distributed randomly into three groups: ten sets of three maximum repetitions (10x3), three sets of ten maximum repetitions (3x10) and five sets of six maximum repetitions (5x6) for each muscular group per training session. Maximum strength (1RM test) and muscle thickness (MT) were evaluated as outcomes. Results A significant main effect (p=0.001) of time on maximum strength was observed for the three groups, but no significance was observed (p>0.05) in time x group interactions. A significant main effect (p=0.001) of time was observed on MT for biceps, triceps and vastus lateralis, without significant differences for time x group interactions. Significant correlations were found between maximum strength and muscle thickness after general statistical analyses for all protocols. Conclusion Improvements in maximum strength and muscle thickness are similar when repetition volumes are equalized through the number of series and repetitions. Level of evidence I; Therapeutic studies, investigation of treatment results.

RESUMO Introdução Existem poucos estudos sobre a eficácia de modelos de treinamento com conjuntos de alto volume por sessão em grupos musculares específicos. Objetivos O objetivo do estudo foi investigar os efeitos de diferentes repetições do treinamento de resistência (TR) com volumes equalizados nas adaptações musculares. Métodos Este estudo tem desenho experimental com 47 voluntários que realizaram oito semanas de TR depois de serem distribuídos randomicamente em três grupos: dez séries de três repetições máximas (10x3), três séries de dez repetições máximas (3x10) e cinco séries de seis repetições máximas (5x6) para cada grupo muscular por sessão de treinamento. A força máxima (teste de 1RM) e a espessura muscular (EM) foram avaliadas como desfecho. Resultados Verificou-se efeito significativo (p = 0,001) sobre o tempo na força máxima nos três grupos, contudo, nenhuma significância (p > 0,05) foi observada nas interações entre tempo e grupo. Constatou-se efeito significativo (p = 0,001) do tempo sobre a EM para bíceps, tríceps e vasto lateral, sem diferenças significativas nas interações entre tempo e grupo. Correlações significativas foram encontradas entre força máxima e espessura muscular depois das análises estatísticas gerais para todos os protocolos. Conclusões A melhora da força máxima e da espessura muscular é semelhante quando o volume de repetições é equalizado considerando o número de séries e repetições. Nível de evidência I; Estudos terapêuticos, investigação dos resultados do tratamento.

RESUMEN Introducción Existen pocos estudios sobre la eficacia de modelos entrenamiento con conjuntos de alto volumen por sesión en grupos musculares específicos. Objetivos El objetivo del estudio fue investigar los efectos de diferentes repeticiones del entrenamiento de resistencia (ER) con volúmenes ecualizados en las adaptaciones musculares. Métodos Este estudio tiene diseño experimental con 47 voluntarios que realizaron ocho semanas de ER después de ser distribuidos aleatoriamente en tres grupos: diez series de tres repeticiones máximas (10x3), tres series de diez repeticiones máximas (3x10) y cinco series de seis repeticiones máximas (5x6) para cada grupo muscular por sesión de entrenamiento. La fuerza máxima (test de 1RM) y el espesor muscular (EM) fueron evaluados como conclusión. Resultados Se verificó efecto significativo (p = 0,001) sobre el tiempo en la fuerza máxima en los tres grupos, sin embargo, ninguna significancia (p> 0,05) fue observada en las interacciones entre tiempo y grupo. Se constató efecto significativo (p = 0,001) del tiempo sobre el EM para bíceps, tríceps y vasto lateral, sin diferencias significativas en las interacciones entre tiempo y grupo. Fueron encontradas correlaciones significativas entre fuerza máxima y espesor muscular después de los análisis estadísticos generales para todos los protocolos. Conclusiones La mejora de la fuerza máxima y del espesor muscular es semejante cuando el volumen de repeticiones es ecualizado considerando el número de series y repeticiones. Nivel de evidencia I; Estudios terapéuticos, investigación de los resultados del tratamiento.

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.

Effects of a short-term of whole-body, high-intensity, intermittent training program on morphofunctional parameters.

BACKGROUND: Few studies have analyzed the application of high-intensity interval training (HIIT) using exercises with body weight among the morphofunctional parameters. AIM: To analyze and compare the effects of six weeks of high-intensity intermittent calisthenic training (HIICT) and moderate intensity, continuous exercise (MICT) on body composition, hypertrophy, and strength. MATERIALS AND METHODS: Twenty-five active, healthy adults were randomized in either the HIIT group (n = 14) or the MICT group (n = 11). The HIIT group performed high-intensity intermittent calisthenic training based on full body exercise. The training session involved 5 min of warm-up followed by 20 sets of 30s all-out exercise and 30 s of passive recovery between sets. Jumping jack, mountain climber, burpee and squat jump were used. The MICT group performed continuous moderate running (5 min of warm-up followed by 20 min of running with intensity fixed at 80% of maximum heart rate). Training for both groups was performed three times weekly on nonconsecutive days. All subjects underwent anthropometric measurements and functional tests. Muscle thickness was also measured. RESULTS: There were no significant changes observed in any anthropometric measurements in both groups. Regarding the functional tests, the analysis of the percentage changes revealed advantages of HIICT over MICT in push-ups only (p = 0.02). The muscular thickness of lower and upper limbs did not present significant differences in the pre- and post-times or between groups (p > 0.05). CONCLUSION: When compared to MICT, HIIT improved push-up effects, without generating significant changes in body composition and muscle thickness.