Efeito agudo do exercício físico em diferentes horas do dia sobre o desempenho cognitivo em humanos

Abstract

Physical exercise can have some acute effects causing transient physiological changes in the functioning of the cognitive system, reflecting changes in the performance of tasks involving reaction time to a stimulus, selective attention, and memory. The type of exercise can also result in different physiological responses according to its intensity and association or not with another task. In addition, the time of the day when exercise is performed can also influence its acute effects. Thus, the present thesis aims to determine the acute effects of different types of physical exercise on cognitive responses at specific times of day. To achieve this objective, three experimental studies were conducted considering the performance in cognitive tests conducted before and after 1) different exercise intensities (60%, 80 and 95% PMI); 2) maximum vertical jump exercise at different times of the day (morning-night); 3) physical exercise sessions combined or not with a cognitive dual task. The main results were that 1) the variation in exercise intensity alters its acute effect on cognitive responses, 2) the high-intensity exercise improves the performance of a cognitive task requiring attention, 3) the acute cognitive responses from simple reaction time and selective attention are better at the night, and 4) when the physical exercise is combined with a dual cognitive task, there is a positive acute effect on tasks involving attention. These findings have some practical applications to the sports, especially regarding the insertion of this scientific knowledge in the promotion and organization of physical training routines, mainly in modalities that envolve concentration and selective attention. In daily and professional life, physical activities for health promotion in general could include short bouts of high-intensity exercise, or a dual cognitive task configuration in longer and moderate sessions performed before important actions requiring fast and accurate cognitive responses, in addition to considering the best time of day to enhance positive results.