Effects of Muscular Glycogen Supercompensation and Depletion and Creatine Supplementation in Metabolic Contribution in Young Runners: a double blind randomized study

• Grant number: 21/14576-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2022
• End date: November 30, 2023
• Field of knowledge: Health Sciences - Nutrition
• Principal Investigator: Marcelo Papoti
• Grantee: Matheus Simionato Firmino
• Host Institution: Escola de Educação Física e Esporte de Ribeirão Preto (EEFERP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Both alactic and lactic anaerobic metabolism are determinant factors of anaerobic capacity (AC). The present study aims to investigate if muscular glycogen content and/or creatine supplementation change AC in runners. For this, two experiments will be happened with 24 volunteers each. In first experiment, the participants will perform three visits in laboratory. Initially, a familiarization with gas analysis technique and incremental test in order to measure the exercise intensity at maximal oxygen uptake (iVO2max) will be executed. After 24 to 72h, in second visit, will occur the first 100% of iVO2max test until exhaustion (Tlim) to establish a baseline alternative test of maximal accumulated oxygen deficit (MAODalt). Followed by a protocol to depletion muscular glycogen. Next, volunteers will receive alimentation with low carbohydrate and a solution with zero, moderate or high carbohydrate. In third visit, 24h after second visit, a new Tlim will be performed to determine MAODalt under the influence of pre-established conditions. Furthermore, second experiment has similar experimental design. The volunteers will perform familiarization and incremental test. One to three days later, the baseline MAODalt by Tlim will be carried out. Therefore, volunteers will receive a creatine supplement or placebo. After seven days, a new Tlim will be applied to determine MAODalt under these two circumstances. During Tlim of both experiments will be considered oxygen consumption and heart rate. Always after Tlim, electromyographic signals will be measured and also, for 10 minutes, excess post-exercise oxygen consumption and blood lactate. In order to estimate metabolic participation, the calculations will be conducted through GEDAE-LaB software. For statistics, will be used Baysian analysis to verify differences (BF10) and effects (BFincl).