Efeito agudo do exercício contrarresistência com restrição de fluxo sanguíneo nos marcadores da função endotelial

• Autor(a) principal: Fernandes Júnior, Márcio Lopes
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8264
• topic: Blood flow-mediated dilation; Vascular occlusion; Nitric oxide; Platelet aggregation; Dilatação fluxo-mediada da artéria braquial; Oclusão vascular; Óxido nítrico; Agregação plaquetária; Sistema cardiovascular; Endotélio vascular; Plaquetas (Sangue) Agregação; Exercícios físicos Aspectos fisiológicos; CNPQ::CIENCIAS DA SAUDE::EDUCACAO FISICA

Introduction: Cardiovascular health is related to the integrity of the vascular endothelium, which can be monitored by the blood flow-mediated dilation of the brachial artery (FMD). Resistance training with blood flow restriction (BFR) has been chronically investigated about its effects on strength and hypertrophy, but acutely, it lacks analysis based on biochemical markers that can help to understand their impact on health. Objective: To compare the acute effects of resistance exercise with and without BFR on endothelial function. Method: Ten young male adults with a mean age of 23 ± 3 years participated in the study. FMD was measured by ultrasound before and after exercise in each condition. Blood samples were collected to determine nitrite and platelet aggregation values. Participants underwent a knee extension and a leg press exercise routine under three experimental conditions, in random order: 1) low intensity with restricted blood flow; 2) low intensity with free blood flow; and 3) high intensity with flow blood flow. Low intensity condition consisted of three sets of 15 repetitions at 30% 1RM, while high intensity consisted of three sets of eight repetitions at 80% 1RM. The applied blood flow restriction was 50% of the popliteal artery occlusion pressure. Results: No significant differences were observed in any of the FMD-related variables in the three experimental conditions. Plasma nitrite concentrations and platelet aggregation had no major effect of time, nor significant differences between the conditions tested. Conclusion: The exercise protocols employed in the present study were not able to significantly affect the responses induced in endothelial function, nitrite and platelet aggregation, which indicates that such exercise conditions do not appear to represent cardiovascular risk from a hemostatic point of view, at least in healthy young men, as the sample that constituted the present study