RESUMO
This study aimed to determine the neurophysiological mechanisms underlying the effects of aerobic exercise, which influence brain O2 consumption, on cognitive enhancement. Sixteen healthy men were asked to complete a 2-back test at rest and after moderate and high-intensity aerobic exercise. During the 2-back test, hemodynamic changes within the prefrontal cortex were assessed using high-density functional near-infrared spectroscopy. Scores of the 2-back test, regardless of the exercise intensity, were positively correlated with the hemodynamic changes within the right and left dorsolateral prefrontal cortex (DLPFC). During an 2-back test, there were differences in the hemodynamic changes within the DLPFC with moderate and high-intensity exercise conditions. In the 2-back condition, the accumulated oxyhemoglobin within the right DLPFC after moderate intensity exercise was 7.9% lower than that at baseline, while the accumulated oxyhemoglobin within the left DLPFC was 14.6% higher than that at baseline after high-intensity exercise. In response to the 2-back test, the accumulated oxygenated hemoglobin within the left DLPFC after high-intensity exercise increased more significantly than that observed after moderate intensity exercise. These results show that the right DLPFC consumes O2 more efficiently in response to moderate intensity aerobic exercise than in response to high-intensity aerobic exercise.