Effects of aerobic training with blood flow restriction in the expression of mitochondrial and protein synthesis pathways

• Grant number: 14/16440-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2015
• End date: February 28, 2017
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Mara Patricia Traina Chacon Mikahil
• Grantee: Guilherme Defante Telles
• Host Institution: Faculdade de Educação Física (FEF). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 15/06994-3 - Effects of aerobic training with blood flow restriction in the expression of mitochondrial and protein synthesis pathways, BE.EP.IC

Abstract

Several studies have been shown the functional and morphological adaptations of traditional training methods such as endurance training (ET) and resistance training (RT), which usually improves cardiovascular and neuromuscular fitness respectively. However, a new training method have been shown be able to improve neuromuscular and cardiovascular gains in only one training protocol, called endurance training with blood flow restriction (ET + BFR). Although the mechanism for these gains occur are not well known, several factors may be related to the increased respiratory capacity and muscle hypertrophy, and increased protein synthesis related to mitochondrial biogenesis, ribosomal biogenesis, and the synthesis of myofibrillar proteins. However, the response of molecular markers responsible for these pathways have not been investigated from an aerobic training protocol with blood flow restriction. In this sense, it is important to investigate the molecular mechanisms that may be responsible for the morphological and functional adaptations arising from this training method. Previously, the study proposal was to investigate the effect of TA + RFS in molecular markers coming from a chronic period of training. Considering the justification of this study, the proposed new objective is to investigate the acute effects of TA+RFS in the expression of pathways involved in protein synthesis and mitochondrial. To achieve this goal the sample will consist of 10 young men who participate in the study voluntarily. The 10 volunteers will participate in three different experimental situations: TA+RFS, TA and TF in which the TA+RFS and the TA will be performed on a cycle ergometer, with 15 and 30 minutes long respectively and corresponding intensities to 40% and 70% of VO2max respectively; TF will consist of the leg press exercise, being held 4 sets of 10 repetitions, with an intensity of 70% of one repetition maximum (1-RM). All 4 volunteers held muscle biopsies, where a biopsy is performed prior to the experimental period and another biopsy happen after each of the three training sessions. Each workout and biopsy will be separated by an interval of one week. Gene expressions will be analyzed in PGC-1±, TFAM, COXIV, VEGF, HIF1-±, HSP72, MnSOD, Hexokinase, MuRF-1, atrogin-1 and GAPDH and protein expressions of mTOR, p70S6K, eEF2 and p53. Since this protocol is able to generate increases in both strength and hypertrophy, as oxygen consumption, the hypothesis of this study is that the TA+RFS stimulates the expression of the protein synthesis pathways and mitochondrial biogenesis and this happens in the same proportion as isolated training.