Efeitos agudos de diferentes intensidades de treinamento físico sobre a cinética e variabilidade da frequência cardíaca em jovens saudáveis

• Autor(a) principal: Basso Filho, Marco Antonio
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/0013000006v1m
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/8429
• topic: Treinamento físico; Treinamento intervalado de alta intensidade; Variabilidade da frequência cardíaca; Jovens; Physical training; High intensity interval training; Variability of heart rate; Young; CIENCIAS DA SAUDE::MEDICINA

Introduction: Studies show that high intensity interval training (HIIT) promotes improvements equivalent or even superior to continuous moderate intensity training (IMT). However, HIIT has divergent applications, approaches and results in the literature regarding its physiological repercussions and the parameters that may bring more safety in its prescription. In this context kinetics and heart rate variability (HRV) represent the physiological responses of the autonomic nervous system (ANS) in cardiac autonomic heart rate (HR) modulation, as well as VO2max represents the aerobic functional capacity and, in the rest-exercise transitions and exercise-recovery, can demonstrate the efficiency of different physical training in fitness, adaptation, vagal withdrawal and sympathetic hyperactivity. Objective: To compare the acute effects of different intensities of physical training on the kinetics of HR and HRV, and functional capacity in healthy physically active youngsters. Objective: To compare the acute effects of different intensities of physical training on the kinetics of HR and HRV, and functional capacity in healthy physically active youngsters. Methodology: Clinical crossover performed with 12 physically active young males. The procedure to obtain the data occurred for 4 days with an interval of 48 hours between those days. On the 1st day the participants were submitted to evaluations including the cardiopulmonary exercise test (CPT) for the purpose of verifying VO2max, identifying their aerobic functional capacity, as well as prescribing the protocols. Between the 2nd and 4th day, the three exercise protocols were performed: TCMI (exercise = 21 minutes continuous at 70% of vVO2max), short HIIT (exercise = 29 repetitions of 30 seconds at 100% of vVO2max and recovery = 30 seconds passive to 50% of vVO2max) and long HIIT (exercise = 3 replicates of 4 minutes to 90% of vVO2max and recovery = 3 minutes to 60% of vVO2max). Participants performed 5 minutes of heating at 55% of vVO2max and at the end of the session 3 minutes of recovery at 50% of vVO2max. The recording data of the R-R intervals were recorded with the participant lying in the supine position for 10 minutes before the start of the tests and immediately after the recovery of the sit-in tests for 3 minutes. The behavior of the HR, HRV and VO2max variables were verified in the rest-exercise transition, during exercise and in the exercise-recovery transition. Statistical analysis: The normality of the data was evaluated by the Komolgorov-Smirnov test. In order to evaluate the correlation between HRV indexes after each exercise protocol and VO2peak, the Pearson Correlation Test or the Spearman Correlation Test were used. Two-way ANOVA was used to verify the differences between the variables obtained in each exercise protocol (HRV indices and cardiorespiratory fitness variables). Values of p <0.05 were considered significant. Results: The systolic blood pressure (SBP) variable showed a lower value in the short HIIT when compared to the long HIIT (p = 0.003). The analysis of FCon kinetics showed a statistical difference for the delta time variable (∆T) when we compared the IMT and the long HIIT (p = 0.041), observing that the IMT promoted a greater slowness in the HR response in the rest-exercise transition. The analysis of the HRV during the exercise-recovery phase (off) was different between the long HIIT versus the IMT and the long HIIT versus the short HIIT (p <0.005 and p = 0.012, respectively), and the long HIIT showed greater sympathetic modulation and lower parasympathetic modulation. The comparison of the differences between the deltas of FCoff, the long HIIT showed a lower HR reduction in the initial 60 seconds of recovery when compared to the short HIIT and IMT respectively, presented by delta 30 (p <0.001 and p = 0.034, respectively) and Delta 60 (p = 0.012 and p = 0.037, respectively). The VO2peak variable had a higher value in the long HIIT when compared to the IMT and the short HIIT (p = 0.028 and p <0.001, respectively). Conclusion: In the intergroup comparison the IMT presented better HR values in the rest-exercise transition and the long HIIT obtained better results in the variables VO2peak and FCpeak. In terms of HRV in the exercise-recovery transition the short HIIT demonstrated better adaptation in the autonomic modulation while the long HIIT showed greater sympathetic hyperactivity and consequent cardiac overload.