Repercussões crónicas musculares esqueléticas ao treino com exercícios excêntricos

• Autor(a) principal: Júlio Daniel Barros Pacheco
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://repositorio-aberto.up.pt/handle/10216/87031
• topic: Outras ciências sociais; Other social sciences

Eccentric exercise is a vehicle of enhancement of mechanical and metabolic stress with strong potential to adversely affect the skeletal muscle and when practiced on a unusual or strenuous way induces muscle damage in the requested muscles. However, regularly trained individuals seem to have tolerance to this type of stimulus, a phenomenon partly explained by chronic morphological adaptations on muscle fibers and on intramuscular connective tissue. The objective of this study was to evaluate the changes in the collagen content of eccentric exercise trained quadriceps. Male wistar rats were divided into two groups (n=5 per group): Control (SED) and trained (TR). The TR animals practiced downhill running on a treadmill (-25º; 30meters/minute; 60 minutes) 1x/week, for 8 weeks. Blood activity of Creatin Kinase was measured during the protocol and, after sacrifice, the quadriceps muscle was collected to histological analysis. A progressive protective effect of training to exercise bout was demonstrated by blood activity of Creatin Kinase (p=0,002). there was an increase in muscle fibers cross-sectional area (p=0,000), simultaneously with an increase in the total collagen content and endomysium thickness (p = 0.000) in trained skeletal muscles. It can be concluded in addition to the tolerance effect,that eccentric exercise training induced a remarkable increase in skeletal muscle collagen content in parallel with a slight increase of muscle fibers crosssectional area.