High frequency brain waves increase depending upon exercise intensity and associated with cerebral blood volume: a simultaneous NIRS-EEG study

Abstract

Exercise is proved to have impacts on cerebral hemodynamic changes. Cerebral hemodynamic changes with exercise have been shown in an intensity-dependent from the mild intensity (about 40 % VO₂max) during a graded cycling exercise. However, its association with brain activation is still unknown. In this paper, the relationship between hemodynamic and EEG-changes with exercise was examined at different intensities from low to moderate. The regional cerebral blood volume (rCBV) and the brain waves were monitored by using NIRO 300 and EEG simultaneously with exercise. Nine healthy volunteers performed a 10-minute of cycling with 30-minute rest intervals at the intensity of 20 %, 40 % and 60 % VO₂max. The EEG resulted in a significant increase in their percentage changes of alpha at 20 % and 40 % VO₂max and beta at 40 % and 60 % VO₂max. A significant positive correlation between rCBV and beta wave was also reported (r＝0.53, P < 0.01). These results show that changes in rCBV with exercise have a significant correlation with high frequency brain wave and implicate that exercise-enhanced rCBV in the prefrontal cortex might be associated with brain arousal.