Hemodynamic Changes in Response to Aerobic Exercise: Near-infrared Spectroscopy Study

Area of Science:

• Neuroscience
• Exercise Physiology
• Cognitive Science

Background:

• Aerobic exercise is known to improve cognitive function.
• The precise neurophysiological mechanisms, particularly concerning brain oxygen (O2) consumption in the prefrontal cortex, remain incompletely understood.

Purpose of the Study:

• To investigate the neurophysiological mechanisms linking aerobic exercise-induced changes in brain O2 consumption to cognitive enhancement.
• To examine the effects of different aerobic exercise intensities on cognitive performance and prefrontal cortex hemodynamics.

Main Methods:

• Sixteen healthy men performed a 2-back test at rest and after moderate and high-intensity aerobic exercise.
• High-density functional near-infrared spectroscopy (fNIRS) was used to assess hemodynamic changes in the prefrontal cortex during the cognitive task.
• Correlation analyses were performed between 2-back test scores and hemodynamic changes.

Main Results:

• Cognitive performance on the 2-back test correlated positively with hemodynamic changes in the right and left dorsolateral prefrontal cortex (DLPFC), irrespective of exercise intensity.
• Hemodynamic responses in the DLPFC differed significantly between moderate and high-intensity exercise conditions.
• Moderate-intensity exercise led to a decrease in oxyhemoglobin in the right DLPFC, while high-intensity exercise showed an increase in the left DLPFC.

Conclusions:

• The findings suggest that aerobic exercise modulates prefrontal cortex activity and oxygenation, contributing to cognitive enhancement.
• The right DLPFC demonstrates more efficient O2 consumption in response to moderate-intensity aerobic exercise compared to high-intensity exercise.
• Different exercise intensities elicit distinct hemodynamic responses in specific prefrontal cortex regions, impacting cognitive processing.