Efeitos do treinamento resistido de baixa intensidade em variáveis cardiovasculares e reatividade vascular de ratos

• Autor(a) principal: Macedo, Fabrício Nunes
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/3987
• topic: Fisiologia; Neurociências; Treinamento (Atletismo); Sistema cardiovascular; Exercícios físicos; Cardiovascular system; Coaching (Athletics); Exercise; Neurosciences; Physiology; CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA

Low intensity aerobic training increases cardiac vagal modulation and reduces sympathetic activity. These adaptations are factors to prediction of healthy. Resistance training (TR) is am usual component of fitness programs, however the effects on autonomic regulation are not totally clear. Our hypothesis is low intensity resistance training promotes beneficial adaptations in cardiac autonomic modulation, as aerobic exercise. Therefore, the aim was to evaluate the effects of low intensity TR on blood pressure, cardiovascular autonomic balance and vascular reactivity. One group of animals were submitted to TR, trained group (GT). Control animals (CO) were fictitious trained (no exercise). After 8 weeks of TR with 40% of 1RM (1 Maximal Repetition) or fictitious exercise, blood pressure and pulse interval were recorded and mesenteric artery was removed and sliced in rings for vascular reactivity analysis. The utilized drugs were: Acetilcholine (ACh): 10-9 10-4 M; Nù-nitro-L-arginine methyl ester hydrochloride (L-NAME): 100ìM. The variabilities of pulse interval, blood pressure and spontaneous baroreflex sensitivity (BRS) were also analyzed. TR animals showed an significantly reduction in mean arterial pressure (CO 117.04 ± 2.68 vs GT 105.5 ± 4.28, p=0.045), diastolic arterial pressure (CO 107.71 ± 2.95 vs GT 97 ± 3.42, p=0.001) and heart rate (CO 395 ± 7.1 vs GT 344 ± 13.25, p=0.007) when compared to CO animals. In addition, it was seen in trained animals an increase in cardiac vagal modulation (LF/HF: CO 0.35 ± 0.08 vs GT 0.14 ± 0.03, p=0.034), BRS (CO 0.77 ± 0.01 vs GT 1.05 ± 0.1, p=0.019) and percentage of ACh-induced relaxation of mesenteric arterial rings (pD2: CO 6.2 ± 0.1 vs GT 7.1 ± 0.1, p<0.001) when compared to the CO animals. Furthermore, the addition of L-NAME reduced the ACh-induced relaxation (CO 52 ± 3.2% vs GT 35.8 ± 3.7%, p<0.01). In conclusion, we observed that low intensity TR apparently was able to promote beneficial cardiovascular adaptations mediated by neurohumoral adjustments, being able to be a possible instrument on maintenance and treatment for a healthy life.