Effects of intermittent recovery hypoxia on molecular, metabolic and neuromuscular responses

Abstract

Exposure to hypoxia has been focus of numerous investigations in the area of the science of physiology and physical exercise. Despite the different strategies for combining hypoxia and exercise in order to enhance the adaptations resulting from training, normobaric hypoxia during recovery between efforts presents an interesting strategy, as it can be simulated in any environment and applied in conjunction with high intensity interval efforts (HIIT). This scenario allows individuals to be exposed to hypoxia only during intervals, maintaining their performance during effort. Thus, the objective of this project will be to compare the hematological, molecular, metabolic and neuromuscular responses from training associated with intermittent recovery hypoxia (EN: RH) to training carried out exclusively in hypoxia (EH: RH) and normoxia (EN: RN). Three experiments will be performed using a dynamic knee extension ergometer. In order to analyze the responses related to training associated with intermittent recovery hypoxia and its variants (EH: RH, EN: RH and EN: RN.), Two experiments will be proposed to investigate different acute responses and a third experiment to investigate the response chronic. The first experiment (n: 20) will aim to compare molecular responses, based on muscle and metabolic biopsies through oxygen consumption. The second experiment (n: 20) will aim to compare the hematological (oxygen saturation, oxyhemoglobin, deoxyhemoglobin and total hemoglobin) and neuromuscular responses through Twitch Interpolation Technique (investigation of central and peripheral fatigue). Finally, in the third experiment, the effects of 5 weeks of training followed by a week of taper will be compared to verify adaptations of a training model. For this, thirty participants will be divided into three groups, that is, EN: RH; EN: RN; EH: RH, and will have only one leg exposed to a training model while the other will be used as a control. Before and after training and taper, participants will be subjected to incremental tests to establish anaerobic threshold of both legs, anaerobic power tests for establishing performance index, submaximal tests to motion economy evaluation and time limit tests in order to verify the maximum tolerance of the effort. As a way of analyzing the results, initially data will be subjected to normality and homogeneity tests and then they will be applied in a mixed model, with fixed factors (ie, exposure condition and time of evaluation) and random factors (ie, participants). Training effects will be verified through a Two-way ANOVA, followed by Tukey's post hoc, while the relationship between the parameters will be tested by Pearson's correlation (p <0.05). (AU)