Biomarcadores de responsividade da aptidão cardiorrespiratória ao treinamento aeróbio

Intrinsic and acquired cardiorespiratory fitness (CRF) is positively associated with the maintenance and improvement of health. However, although adherence to physical exercise guidelines brings benefits for most individuals, there is considerable inter-individual variability in CRF responses to regular training. In this regard, investigating the molecular determinants associated with CRF trainability has the potential to generate new biomarkers predictive of the adaptations inherent to different forms of physical exercise and to contribute to more efficient training strategies. Therefore, the main objective of this study will be to investigate serum and skeletal metabolites associated with CRT trainability, assessed by maximum power output (MPO) during a maximal incremental test, in response to 8 weeks of continuous aerobic training (CAT) and high-intensity interval training (HIIT), matched by the same total number of exercise units performed. To this end, two experiments will be conducted. Experiment I: a cross-sectional design, in which 80 sedentary men (aged 18–30) will be divided into two groups based on intrinsic MPP. To analyse the metabolites associated with intrinsic ACR and those that discriminate between individuals with high and low ACR, a maximal incremental test will be performed to determine MPP, followed by the collection of blood and muscle tissue 72 hours later. Experiment II: a randomised, controlled longitudinal study in which 80 subjects will undergo an 8-week intervention in each of the three groups: TAC (40 min/day, 3–4 times/week, 70% HRmax), HIIT (40 min/day, 3–4 times/week, 50–90% HR) or control group (no exercise). Blood serum and vastus lateralis muscle tissue samples will be collected before and after the intervention. In both experiments, blood and muscle tissue samples will be analysed by Proton Nuclear Magnetic Resonance spectroscopy (metabolomics) to quantify polar metabolites. In both experiments, the association of serum and skeletal muscle metabolites with MPP (intrinsic and acquired) will be explored via three analytical strategies: (1) identification of correlations between baseline metabolite concentrations and intrinsic and acquired MPP; (2) differences in baseline metabolite concentrations between subgroups of individuals exhibiting greater and lesser magnitudes of intrinsic and acquired MPP (based on the 1st and 3rd tertiles of the MPP distribution); and (3) the individual contribution of the metabolite to significant metabolic pathways associated with intrinsic and acquired MPP. Metabolites supported by the three levels of evidence will be suggested as candidates for predictors of intrinsic and acquired MPP. The data has not yet been made available due to intellectual property rights. For further information, please contact chaconm@unicamp.br. (2025-03-01)