Impacto da suplementação aguda de nitrato sobre a cinética do consumo de oxigênio nos domínios moderado, pesado, muito pesado e severo do esforço físico: um estudo randomizado, crossover e duplo cego

Abstract

The inorganic nitrate was known as an undesired molecule in the diet with potential harmful effects. However, during the last decade, studies have shown that the nitrate is physiologically recycled in the blood and tissues to act as an alternative substrate in the production of nitric oxide. In turn, nitric oxide contributes significantly regulating many body functions such as muscle contractility, energy metabolism, intercellular messenger, macrophage-mediated cytotoxicity, inhibition of platelet aggregation, blood pressure, blood flow and mitochondrial respiration. Therefore, there is an increasing interest to investigate the effects of nitrate supplementation on nitric oxide production and its effects on exercise. Despite the effect of nitrate on oxygen cost during submaximal exercise is well known, there is controversies over the designation, determination and standardization of exercise intensities. Additionally, no study has investigated the potential ergogenic properties of nitrate to exercise during the exercise in the severe domain, which is an exercise intensity above the maximum oxygen uptake. Thus, in order to contribute to acknowledge with this thematic, this dissertation presents two articles: 1) a literature review with the main acute and chronic effects of nitrate supplementation and its relation to nitric oxide formation an exercise performance; 2) An experimental study using a counterbalanced , randomized and double blind design to investigate the effects of acute nitrate supplementation on VO2 kinetics in moderate, heavy, very heavy and severe domains.