Associations between incremental exercise capacity and multimodal brain characteristics across training levels

Area of Science:

• Neuroscience
• Exercise Physiology
• Brain Imaging

Background:

• Endurance training induces brain plasticity in areas like the prefrontal cortex and hippocampus.
• Previous studies used cross-sectional and longitudinal designs to show these effects.
• This study investigates the relationship between endurance indicators and brain characteristics across varying training levels.

Purpose of the Study:

• To examine how endurance indicators relate to multimodal neural characteristics.
• To explore differences in brain-physiology coupling across different endurance training levels.

Main Methods:

• Thirty-two males were categorized into high-level athletes, moderately trained runners, and controls.
• Structural MRI and resting-state functional MRI were used.
• Graded exercise testing assessed maximal oxygen consumption, lactate threshold, and individual lactate threshold (ILT).
• Gray matter volume, fractional amplitude of low-frequency fluctuations, and degree centrality were analyzed.
• Correlation analyses with FDR correction and sensitivity analyses were performed.

Main Results:

• Exercise capacity indicators correlated with neural characteristics in prefrontal, premotor, precuneus, temporal, and cerebellar regions.
• Negative associations were found in the thalamus and inferior cerebellum before correction.
• FDR correction resulted in more selective associations.
• Subgroup analyses indicated different patterns across training levels, though less stable.

Conclusions:

• Exercise capacity is linked to distributed brain characteristics, with robust associations remaining after corrections.
• Brain-physiology coupling may differ by training stage, with moderately trained individuals showing broader patterns and high-level athletes showing focal prefrontal associations.
• These subgroup findings require cautious interpretation due to stability issues.