Efeitos da interação do excesso de massa corporal e exercício físico sobre variabilidade da frequência cardíaca

• Ano de defesa: 2019
• Autor(a) principal: Dias, André Rodrigues Lourenço
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Faculdade de Educação Física (FEF); UFMT CUC - Cuiabá; Programa de Pós-Graduação em Educação Física
• Palavras-chave em Português: Modulação autonômica; Exercício físico; Exercício intervalado; Ritmo circadiano; Indice de massa corporal; CNPQ::CIENCIAS DA SAUDE::EDUCACAO FISICA; Autonomic modulation; Physical exercise; Interval exercise; Circadian rhythm; Body mass index
• Link de acesso: http://ri.ufmt.br/handle/1/2765

High intensity interval exercise (HIIE) promotes body mass reduction similarly to the moderate intensity continuous exercise (MICE), but with 40% less time spent. However, HIIE may have the cost of keeping lower heart rate variability (HRV) for longer than MICE, indicating increased cardiac autonomic stress. Individuals with excess body mass are more exposed to adverse changes in the circadian rhythm of HRV than their peers with normal body mass. However, the effect of excess body mass on ambulatory HRV after stress caused by physical exercise is still unknown. Thus, the present study had as objectives a) to verify the effect of excess body mass on ambulatory HRV after MICE, b) to compare the effects of HIIE and MICE on ambulatory HRV in individuals with excess body mass. The study included men aged 18 to 26 years, BMI between 18.5-39.9 kg/m2, non-smokers and non-trained. The study consisted of three sessions: MICE (30min; 50-60% of heart rate reserve - HRR), HIIE (20 min; 80-90% of HRR) and control without exercise – CT (30 min), followed by analysis of 24 hours ambulatory HRV. The SDNN, RMSSD, Ln-LF and Ln-HF indices of HRV were analyzed. In relation to the results of objective "a", it is observed that the areas under the curve of ambulatory period of the RMSSD (p = 0.007), Ln-LF (p = 0.004) and Ln-HF (p = 0.009) were higher after MICE compared to CT session in the group with excess body mass. In both sessions, there were no differences between groups in the ambulatory HRV indices. As a result of objective "b", the area under the curve of the Ln-LF index in the sleep period after HIIE was superior compared to CT (43.31 ± 8.59 ms2*h vs. 41.11 ± 7.28 ms2*h, p = 0.034, Hedges gav = 0.26). It is concluded for the objective "a" that only individuals with excess body mass presented increased autonomic cardiac autonomic modulation after MICE. For objective "b" it is concluded that HIIE increased autonomic cardiac modulation during sleep in individuals with excess body mass, indicating that HIIE, contrary to expectations, increases cardiac protection during sleep in this population.