The effect of high-intensity interval training on post-exercise oxygen consumption: a meta-analysis / Efecto del entrenamiento de intervalos de alta intensidad sobre el consumo de oxígeno después delejercicio: metaanálisis / Efeito do treinamento intervalado de alta intensidade sobre o consumo de oxigênio depois do exercício: metanálise

ABSTRACT Introduction: The objective of this study was to present a systematic review and meta-analysis to compare total excess post-exercise oxygen consumption (EPOC) for two training intervention models in healthy individuals, and the secondary objective was to understand whether oxygen consumption after exercise could really promote a meaningful help. Design: To design a meta-analysis review to compare two training intervention models (experimental: high-intensity interval training; and control: continuous moderate-intensity) and their effects on total EPOC in healthy individuals. Participants: Seventeen studies were considered to be of good methodological quality and with a low risk of bias. Methods: Literature searches were performed using the electronic databases with no restriction on year of publication. The keywords used were obtained by consulting Mesh Terms (PubMed) and DeCS (BIREME Health Science Descriptors). Results: The present study findings showed a tendency (random-effects model: 0.87, 95%-CI [0.35,1.38], I2=73%, p<0.01) to increase EPOC when measured following high-intensity interval training. Conclusions: Our study focused on the analysis of high- and moderate-intensity oxygen uptake results following exercise. Despite the growing popularity of high-intensity interval training, we found that the acute and chronic benefits remain limited. We understand that the lack of a standard protocol and standard training variables provides limited consensus to determine the magnitude of the EPOC. We suggest that longitudinal experimental studies may provide more robust conclusions. Another confounding factor in the studies investigated was the magnitude (time in minutes) of VO2 measurements when assessing EPOC. Measurement times ranged from 60 min to 720 min. Longitudinal studies and controlled experimental designs would facilitate more precise measurements and correct subject numbers would provide accurate effect sizes. Systematic reviewb of Level II studies.

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RESUMO Introdução: O objetivo deste estudo foi apresentar uma revisão sistemática e metanálise para comparar os efeitos de dois modelos de intervenção de treinamento sobre o consumo excessivo de oxigênio pós-exercício (EPOC) em indivíduos saudáveis em treinamento, e o objetivo secundário foi entender se o consumo de oxigênio depois de exercício realmente pode proporcionar ajuda substancial. Objetivo: Elaborar uma revisão de metanálise para comparar um modelo de treinamento de duas intervenções (experimental: treinamento intervalado de alta intensidade, e controle: contínuo de intensidade moderada) e o efeito sobre o EPOC total em indivíduos saudáveis. Participantes: Os 17 estudos foram considerados de boa qualidade metodológica e baixo risco de viés. Métodos: As buscas bibliográficas foram realizadas nos bancos de dados eletrônicos sem restrição de ano de publicação. Os descritores usados foram obtidos em MeSH (PubMed) e DeCS (Descritores em Ciências da Saúde da BIREME). Resultados: Os achados do presente estudo mostraram uma tendência (modelo de efeitos aleatórios: 0,87, IC 95% [0,35;1,38], I ² = 73%, p < 0,01) de aumento do EPOC quando as medidas foram realizadas depois de treinamento intervalado de alta intensidade. Conclusões: Nosso estudo concentrou-se na análise dos resultados de alta e moderada intensidade no consumo de oxigênio depois do exercício. Apesar da crescente popularidade do treinamento intervalado de alta intensidade, descobrimos que os benefícios agudos e crônicos permanecem limitados. Entendemos que a falta de um protocolo e variáveis padronizadas de treinamento fornecem consenso limitado para determinar a magnitude do EPOC. Sugerimos que estudos experimentais longitudinais podem fornecer conclusões mais robustas. Outro fator de confusão nos estudos investigados foi a magnitude (tempo em minutos) das medidas do VO2na avaliação do EPOC. Os tempos de medição variaram de 60 a 720 min. Estudos longitudinais e projetos experimentais controlados facilitariam medições mais precisas e números corretos de indivíduos forneceriam tamanhos de efeito precisos. Nível de evidência II; Revisão sistemáticabde Estudos.

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.

Physical training attenuates right ventricular dysfunction in rats exposed to cigarette smoke

Abstract Aim: To evaluate the functional and morphological cardiac variables of rats exposed to chronic cigarette smoke (ECS) and to analyze the influence of exercise training on any cardiac remodeling. Methods: Male Wistar rats were assigned into four groups: control animals (C, n=10); control trained rats (CT, n=10), that underwent swimming physical training; ECS rats (E, n=10), that received the smoke of 40 cigarettes/day; and ECS plus trained rats (TE, n=10), that received the cigarette smoke plus the swimming training protocol, for 15 weeks. At the end of the experiment, the animals underwent hemodynamic measurements of the right ventricle (RV) and morphological examination. Results: There was a decrease in the body weight of E, TE and CT groups (p<0.05). RV pressure (maximum systolic, diastolic initial and end-diastolic) was increased in the E and ET groups (p <0.05), while there was a decrease in RV maximum derivative pressure, RV minimum derivative pressure (+dP/dt and -dP/dt) and systolic duration in the TE group (p <0.05). Heart rate increased in the E group (p<0.05). The lung weight/body weight ratio was higher in the TE group (p=0.008). Fluid retention was increased in the RV, left ventricle (LV) and lung of the E group (p<0.001). Conclusion: ECS caused right ventricular dysfunction, pulmonary hypertension and cardiac remodeling. Physical training attenuated the effects of ECS for heart rate responses and the morphological variables of the RV, LV, and the lung.

Prior exercise training and experimental myocardial infarction: A systematic review and meta-analysis

Exercising prior to experimental infarction may have beneficial effects on the heart. The objective of this study was to analyze studies on animals that had exercised prior to myocardial infarction and to examine any benefits through a systematic review and meta-analysis. The databases MEDLINE, Google Scholar, and Cochrane were consulted. We analyzed articles published between January 1978 and November 2018. From a total of 858 articles, 13 manuscripts were selected in this review. When animals exercised before experimental infarction, there was a reduction in mortality, a reduction in infarct size, improvements in cardiac function, and a better molecular balance between genes and proteins that exhibit cardiac protective effects. Analyzing heart weight/body weight, we observed the following results - Mean difference 95% CI - -0.02 [-0.61,0.57]. Meta-analysis of the infarct size (% of the left ventricle) revealed a statistically significant decrease in the size of the infarction in animals that exercised before myocardial infarction, in comparison with the sedentary animals -5.05 [-7.68, -2.40]. Analysis of the ejection fraction, measured by echo (%), revealed that animals that exercised before myocardial infarction exhibited higher and statistically significant measures, compared with sedentary animals 8.77 [3.87,13.66]. We conclude that exercise performed prior to experimental myocardial infarction confers cardiac benefits to animals.

Energy expenditure and intensity of HIIT bodywork® session

Abstract Aim: Several programs using total body weight exercise methods have been applied in several populations especially using HIIT. The present study assessed the oxygen consumption, heart rate, and energy expenditure of a HIIT body work® session. Methods: Twelve male participants performed 20 minutes of a HIIT body work, consisting of 20 sets of 30 seconds of stimulation in all-out intensity, followed by 30 seconds of passive recovery. Five cycles were performed for each exercise (jumping jack, burpee, mountain climb, and squat jump). Results: The mean VO2 of the session was 34 ± 7 ml.kg.min-1 (80.35% of the VO2 peak obtained in the session). The energy expenditure of the session was 251±27 kcal (13±1 kcal.min-1) and 39 ± 8 kcal (75±1 kcal.min-1) during the recovery time. The heart rate values were 160±18 bpm (91% of the peak HR of the session) and 125±22 bpm (71%) in recovery. In addition, significant differences (p<0.05) in maximal VO2 were found between jumping jack, mountain climber, burpee and squat jump. Conclusion: Based on the present data, a HIIT bodywork® session presented energy expenditure as a typical high-intensity exercise profile.

Multivariate linear regression analysis to evaluate multiple-set performance in active and inactive individuals

Abstract Aim: To determine how EMG, anthropometric, and psychological factors, and physical activity levels affect isokinetic peak torque performance (IPT) of multiple set exercise sessions. Methods: 20 participants (27±7 years old), classified as active (A=10) and inactive (I=10), performed 10x10:40secs of maximal unilateral knee flexions and extensions at 120o.s-1. The IPT, EMG, glucose, LDH, and lactate concentrations and perceptions of pain, effort, recovery. Results: Active volunteers showed higher muscularity (52±5 vs 47±4 cm; p<0.05), PTI (262±4 vs 185±4 Nm; p<0.05), relative lower drop in performance (14±2 vs 27±3% ; p<0.05), major MDF (83±1 vs 76±1 Hz; p<0.05), lower log -Fins5 (-12.9±0.3 vs -12.7 ± 0.3 Hz; p<0.05), smaller subjective perception of effort (14.8±0.3 vs 17.0±0.3) and higher subjective perception of recovery (14.2±0.2 vs 12.3±0.3). There was a significant interaction between relative fatigue and the number of sets (F=6.18; p<0.001). Stepwise multiple regressions revealed that subjective perception of recovery best explained the fatigue level generated in the active volunteers [fatigue level= 85.084-5255(SPR)] while for body mass was the best determinant for the inactive group [fatigue level = -21.560 +1.828(BMI)]. Conclusion: Data from the present analysis suggest that physically active individuals show higher torque development and a smaller fatigability index when compared to inactive individuals. Among the fatigue models studied, it is possible that alterations in biochemical components, psychophysiological and EMG are not sensitive to the direct influence of the fatigue dynamics protocol, both in active or inactive individuals.

Description of training loads using whole-body exercise during high-intensity interval training

OBJECTIVES: To describe external training load and internal training load through sets of a single session of high-intensity interval training (HIIT) body work. METHODS: Twenty male individuals (24±3 years) performed a HIIT body work protocol consisting of a single bout of exercise with 1:1 stimuli. The exercises used were 30 min in duration with "all-out" intensity. The exercises included jumping jacks, mountain climbers, burpees and squat jumps, totaling 20 min of exercise. During exercise, total movement capacity, blood lactate measurement, ratings of perceived exertion and recovery, training load and intensity were monitored. RESULTS: The single bout examined showed a total of 382±89 movements. Differences (p<0.01) in the total amount of movement for each exercise were noted, reflecting the difficulty of maintaining exercise over time. Increases in lactate concentrations (before: 0.98±0.16, after: 14.10±1.66; mmol/L) were found postexercise. Significant differences (p<0.01) were found after the fifth set, and the values for movement capacity remained higher than the values of the first set, demonstrating high load in a single session. No differences in ratings of perceived exertion (RPE) during the sets were found. However, the ratings of perceived recuperation from the second set were significantly (p<0.01) lower than those from the first set. CONCLUSIONS: The exercise protocol used in this study was of high intensity and produced large values for stress during performance, with increases recorded for the internal load indicators.