Athlete Brain: Impact of High-Intensity Endurance Training on Brain Structure, Function, and Perfusion

Abstract

Endurance athletes have profound cardiovascular adaptations to support their outstanding aerobic performance. However, their cerebral adaptations, including the structure, neural activity, and perfusion, have not been characterized comprehensively. Therefore, the purpose of this study was to compare young male, highly trained endurance runners with age- and sex-matched sedentary adults. Fifteen athletes and 16 sedentary adults were enrolled. All participants underwent magnetic resonance imaging （MRI） using a 3-tesla scanner at the supine resting condition. Brain volume, cortical thickness, white matter （WM） fiber integrity, functional connectivity, and cerebral blood （CBF） and cerebrospinal fluid （CSF） flows were measured. Results showed that endurance athletes had higher WM fiber integrity than sedentary participants, as assessed by fractional anisotropy at the corpus callosum, corona radiata, and superior fronto-occipital fasciculus. Furthermore, functional connectivity between the posterior cingulate and the right frontal pole was more robust in endurance athletes than in sedentary adults. Brain volume, cortical thickness, CBF, and CSF flow were not different between groups. Collectively, these findings suggest that high-intensity endurance training strengthens the brain structural and functional connectivity in young male adults.