Efeitos do treinamento intervalado de alta intensidade vs. treinamento aeróbio contínuo, em condições de volumes equiparáveis, sobre a função autonômica cardíaca de jovens sedentários
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Data
2022-01-24
Autores
Silveira, Natalia de Sousa
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Universidade Estadual Paulista (Unesp)
Resumo
Atualmente, a inatividade física consiste em um dos principais fatores de risco associados a ocorrência de mortes por doenças cardiovasculares. Adicionalmente, disfunções autonômicas cardíacas têm sido observadas em indivíduos com baixos níveis de atividade física habitual, desempenhando um papel importante na ocorrência de doenças cardiovasculares. Neste sentido, o monitoramento da variabilidade da frequência cardíaca (VFC) tem sido utilizado como um método avaliativo simples e não invasivo para acessar alterações promovidas no sistema nervoso autonômico cardíaco, sendo o aumento da VFC indicativo de aumento do tônus vagal e melhora da função autonômica. Estudos recentes apontam para o treinamento aeróbio, principalmente de alta intensidade, como uma estratégia para promover aumento na modulação parassimpática. O treinamento intervalado de alta intensidade (HIIT) tem sido sugerido como um método alternativo para promover melhora na função autonômica cardíaca em magnitude similar, ou ainda superior, ao tradicional treinamento aeróbio contínuo (TAC). Entretanto, a falta de controle apropriado dos volumes de treinamento entre protocolos em estudos prévios dificulta a real compreensão da manipulação da intensidade de exercício sobre a função autonômica cardíaca. O objetivo deste estudo foi testar a eficácia do treinamento HIIT, comparado a um mesmo volume de TAC, sobre a função autonômica cardíaca de indivíduos jovens, saudáveis e fisicamente inativos. Participaram deste estudo 69 homens sedentários e saudáveis, com idades entre 18 e 31 anos, que foram alocados de forma randômica nos grupos TAC, HIIT e Controle (CO). Os participantes foram previamente submetidos a realização de teste de esforço máximo e avalição autonômica. Após, o grupo CO passou 8 semanas sem se exercitar e os grupos TAC e HIIT passaram por 8 semanas de intervenção. Avaliações autonômica, cardiorrespiratória e de composição corporal foram realizadas Pré e Pós 8 semanas de intervenção. A VFC foi analisada através do domínio tempo e frequência. Comparações entre e intra- grupos foram realizadas por Equações de Estimativa Generalizada (GEE), adotando-se nível de significância (α) de 5% (P < 0,05). Para a análise no domínio da frequência, apenas a variável LF Power (n.u) apresentou interação grupo*momento obtendo redução do momento Pré para o momento Pós (14,63%) e aumentou no momento Pós do grupo HIIT quando comprado ao grupo CO (33,7%). Já no domínio do tempo observamos valores significativos apenas em momento, houve aumento no momento Pós em relação ao Pré na variável RMSSD (13,31%, P = 0,059), já na frequência cardiaca de repouso (MeanHR), houve redução no momento Pós quando comparado ao Pré (4,05%, P = 0,001) por fim, a média dos intervalos iRR (MeanRR) apresentou aumento no momento Pós em relação ao momento Pré (4,56% , P < 0,001). Para a composição corporal foi notado que o grupo HIIT apresentou redução significativa no percentual de gordura corporal no momento Pós treinamento (-1,89%, P = 0,001) sem alterações para os grupos TAC e CO. Em conclusão, para homens jovens e sedentários o HIIT se mostrou uma alternativa mais eficaz que o TAC para promover melhora na modulação autonômica cardíaca, que foi acompanhada durante o estudo.
Currently, physical inactivity is one of the main risk factors associated with the occurrence of deaths from cardiovascular diseases. Additionally, cardiac autonomic dysfunctions have been observed in individuals with low levels of habitual physical activity, playing an important role in the occurrence of cardiovascular diseases. In this sense, the monitoring of heart rate variability (HRV) has been used as a simple and non-invasive evaluation method to assess changes promoted in the cardiac autonomic nervous system, with the increase in HRV indicative of increased vagal tone and improvement of autonomic function. . Recent studies point to aerobic training, mainly of high intensity, as a strategy to promote an increase in parasympathetic modulation. High-intensity interval training (HIIT) has been suggested as an alternative method to promote improvement in cardiac autonomic function in a magnitude similar to, or even greater than, traditional continuous aerobic training (CAT). However, the lack of proper control of training volumes between protocols in previous studies makes it difficult to truly understand the manipulation of exercise intensity on cardiac autonomic function. The aim of this study was to test the effectiveness of HIIT training, compared to the same volume of CAT, on cardiac autonomic function in young, healthy and physically inactive individuals. The study included 69 healthy, sedentary men, aged between 18 and 31 years, who were randomly allocated to the TAC, HIIT and Control (CO) groups. The participants were previously submitted to a maximal effort test and autonomic assessment. Afterwards, the CO group spent 8 weeks without exercising and the TAC and HIIT groups underwent 8 weeks of intervention. Autonomic, cardiorespiratory and body composition assessments were performed before and after 8 weeks of intervention. HRV was analyzed through the time and frequency domain. Comparisons between and within groups were performed using Generalized Estimating Equations (GEE), adopting a significance level (α) of 5% (P < 0.05). For the analysis in the frequency domain, only the LF Power variable (nu) showed group*moment interaction, obtaining a reduction from the Pre to the Post moment (14.63%) and increased in the Post moment of the HIIT group when compared to the CO group ( 33.7%). In the time domain, however, we observed significant values only at moment, there was an increase in the Post moment in relation to Pre in the RMSSD variable (13.31%, P = 0.059), in the resting heart rate (MeanHR), there was a reduction in the Post moment. when compared to Pre (4.05%, P = 0.001) finally, the average of the iRR intervals (MeanRR) showed an increase in the Post moment in relation to the Pre moment (4.56% , P < 0.001). For body composition, it was noted that the HIIT group showed a significant reduction in body fat percentage at the post-training moment (-1.89%, P = 0.001) with no changes for the TAC and CO groups. In conclusion, for young and sedentary men, HIIT proved to be a more effective alternative than TAC to promote improvement in cardiac autonomic modulation, which was monitored during the study
Currently, physical inactivity is one of the main risk factors associated with the occurrence of deaths from cardiovascular diseases. Additionally, cardiac autonomic dysfunctions have been observed in individuals with low levels of habitual physical activity, playing an important role in the occurrence of cardiovascular diseases. In this sense, the monitoring of heart rate variability (HRV) has been used as a simple and non-invasive evaluation method to assess changes promoted in the cardiac autonomic nervous system, with the increase in HRV indicative of increased vagal tone and improvement of autonomic function. . Recent studies point to aerobic training, mainly of high intensity, as a strategy to promote an increase in parasympathetic modulation. High-intensity interval training (HIIT) has been suggested as an alternative method to promote improvement in cardiac autonomic function in a magnitude similar to, or even greater than, traditional continuous aerobic training (CAT). However, the lack of proper control of training volumes between protocols in previous studies makes it difficult to truly understand the manipulation of exercise intensity on cardiac autonomic function. The aim of this study was to test the effectiveness of HIIT training, compared to the same volume of CAT, on cardiac autonomic function in young, healthy and physically inactive individuals. The study included 69 healthy, sedentary men, aged between 18 and 31 years, who were randomly allocated to the TAC, HIIT and Control (CO) groups. The participants were previously submitted to a maximal effort test and autonomic assessment. Afterwards, the CO group spent 8 weeks without exercising and the TAC and HIIT groups underwent 8 weeks of intervention. Autonomic, cardiorespiratory and body composition assessments were performed before and after 8 weeks of intervention. HRV was analyzed through the time and frequency domain. Comparisons between and within groups were performed using Generalized Estimating Equations (GEE), adopting a significance level (α) of 5% (P < 0.05). For the analysis in the frequency domain, only the LF Power variable (nu) showed group*moment interaction, obtaining a reduction from the Pre to the Post moment (14.63%) and increased in the Post moment of the HIIT group when compared to the CO group ( 33.7%). In the time domain, however, we observed significant values only at moment, there was an increase in the Post moment in relation to Pre in the RMSSD variable (13.31%, P = 0.059), in the resting heart rate (MeanHR), there was a reduction in the Post moment. when compared to Pre (4.05%, P = 0.001) finally, the average of the iRR intervals (MeanRR) showed an increase in the Post moment in relation to the Pre moment (4.56% , P < 0.001). For body composition, it was noted that the HIIT group showed a significant reduction in body fat percentage at the post-training moment (-1.89%, P = 0.001) with no changes for the TAC and CO groups. In conclusion, for young and sedentary men, HIIT proved to be a more effective alternative than TAC to promote improvement in cardiac autonomic modulation, which was monitored during the study
Descrição
Palavras-chave
Aerobic training, Cardiac autonomic modulation, Sedentary lifestyle, Treinamento aeróbio, Modulação autonômica cardíaca, Sedentarismo