Ergogenic effects of sustained or repeated exposure to extreme environmental conditions: impact of training in heat and altitude

• Grant number: 22/15200-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: May 01, 2023
• End date: April 30, 2024
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Marcelo Papoti
• Grantee: Matheus Silva Norberto
• Supervisor: Nikolai Baastrup Nordsborg
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University of Copenhagen, Denmark
• Associated to the scholarship: 21/02403-1 - Effects of intermittent recovery hypoxia on molecular, metabolic and neuromuscular responses, BP.DR

Abstract

Considering that there are several models of exposure to heat and hypoxia and that both have similar signals by the activation of HIF-1, the current project has two experiments; the first one aim to investigate the differences between adaptations to thermal and hypoxic stress on hematological, cardiovascular, muscular and performance parameters in athletes. Assuming that heat and hypoxia can also promote hematological changes through increased plasma volume, the second experiment aims to verify the relationship between the increase in plasma volume and short- and long-term adaptations in untrained subjects. In the first experiment, 30 elite rowers and cyclists will be divided into three groups (i.e., heat stress, hypoxic stress, and control). They will perform a week of evaluation before and after five weeks of training (75 - 85% HRmax). The evaluation weeks will include indirect calorimetry analysis, total hemoglobin mass, plasma volume, incremental testing, blood collections, orthostatic tolerance, and vascular endothelial function. In the second experiment, 60 participants, between men and women, will perform 52 weeks of training (3 to 4 sessions/week; 70 - 80% HRmax). Assessments will be conducted the week before the start of training and weeks 8, 16, and 52 during movement. During the evaluation weeks, the exams and tests will be performed on non-consecutive days, comprising: familiarization with the exercise model, incremental test, body composition, plasma volume, measurement of total hemoglobin mass, orthostatic evaluation (before and after induced volume expansion plasma), analysis of peripheral vascular function, muscle biopsy (analysis of HIF-1 expression) and analysis of endothelial function and vascular sensitivity by infusion of vasoactive drugs. Statistical analyzes between groups and moments will be performed using ANOVA analysis of variance with Bayesian treatment (Jamovi, vs. 1.6, Sidney, Australia). (AU)