Brain Structural and Functional Connectivity in Collegiate Endurance Athletes

Abstract

High‐intensity endurance training elicits profound cardiopulmonary adaptations, but its impact on the central nervous system, particularly the brain neuronal connectivity, remains unclear.PURPOSETo compare the structural and functional brain connectivity between endurance athletes and age‐ and sex‐matched sedentary adults.METHODSFifteen long‐distance male runners (20±1 years) in the university track‐and‐field team and 16 sedentary male students (21±2 years) underwent brain imaging with a 3‐tesla MRI system. Structural brain connectivity was quantified by fractional anisotropy (FA) calculated from diffusion tensor images and analyzed by tract‐of‐interest (TOI) and whole‐brain voxelwise statistics. Functional brain connectivity was assessed by seed‐based network analysis of the resting‐state functional MRI data. Brain volume and cortical thickness were also assessed by T1‐weighted images.RESULTSEndurance athletes had the maximal oxygen uptake of 69.5±3.1 ml/kg/min that is higher than 90 percentiles based on the American College of Sports Medicine guideline. TOI analysis exhibited that FA in the anterior thalamic radiation was significantly higher in the athlete group than the sedentary group (0.421±0.019 vs. 0.397±0.025, p=0.007). Furthermore, voxelwise analysis showed that athletes had a significant elevation of FA across the white matter, including the anterior portions of the corpus callosum, internal capsule, and corona radiata. Within the default mode network, athletes had stronger functional connectivity between the posterior cingulate and the right frontal pole than sedentary participants (p=0.0419 with false discovery rate correction). Regional brain volume and cortical thickness were similar between the athlete and sedentary groups (p>0.05).CONCLUSIONOur findings suggest that high‐intensity endurance training is associated greater brain structural and functional connectivity in young men.