Brain network topology and neural mechanisms in Sanda athletes: a comparative study across training levels.

Purpose: This study investigated the topological organization of brain networks in Sanda athletes across different training levels to elucidate the neural mechanisms underlying the sport's exceptional sensorimotor integration and training-related neural plasticity. Methods: Multimodal magnetic resonance imaging (MRI) data were collected from 35 participants, including elite athletes, second-level athletes, and novices. Using the Automated Anatomical Labeling 116-region atlas (AAL116), structural connectivity (SC) networks were constructed based on fractional anisotropy (FA) derived from diffusion tensor imaging, while functional connectivity (FC) networks were computed using Pearson correlations between regional blood-oxygen-level-dependent (BOLD) time series. Structure-function coupling (SFC) networks were generated as a weighted linear combination of SC and FC. Network differences were assessed using Network-Based Statistic (NBS) and graph-theoretical analyses. Results: Elite athletes exhibited prominent structure-function coupling within visual-motor-executive pathways, whereas novices showed greater involvement of language-rhythm-related pathways. At the global level, elite athletes demonstrated stronger small-world organization and network synchrony, suggesting more efficient information transmission. At the nodal level, the parietal-cerebellar system emerged as a critical hub across the examined networks, with particularly prominent involvement of the right supramarginal gyrus (SMG.R) and right cerebellar lobule VI (CRBL6.R). Discussion: These regions are likely to play a central role in sensorimotor integration and rhythm control. These findings confirm that long-term Sanda training optimizes brain network topology, providing key insights into the neural plasticity of athletic expertise.