Updated · The Transmitter: Neuroscience News and Perspectives · May 19
Marathon Study Links Brain Myelin Drop to 2-Month Recovery, Suggesting Energy Reserve Role
Updated
Updated · The Transmitter: Neuroscience News and Perspectives · May 19
Marathon Study Links Brain Myelin Drop to 2-Month Recovery, Suggesting Energy Reserve Role
3 articles · Updated · The Transmitter: Neuroscience News and Perspectives · May 19
MRI scans of marathon runners showed reduced myelin content in several white-matter tracts immediately after the race, with levels returning to baseline about two months later.
The pattern suggests the brain may tap lipid-rich myelin as a temporary energy reserve during extreme metabolic stress, though the researchers said MRI alone cannot prove myelin lipids were used as fuel.
Mouse studies cited in the report point the same way: under glucose deprivation, myelin metabolism appears to help sustain axonal function while myelin thins.
The findings add to a broader shift from a glucose-only view of brain power toward a model in which astrocytes, oligodendrocytes and neurons share, redistribute and potentially store energy.
That framework could reshape research on exercise, fasting and ketone use, and may open therapies aimed at preserving white matter as both wiring and metabolic support.
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Marathon-Induced Myelin Reduction: Brain Uses Its Own Fat for Fuel, Study Finds
Overview
A recent study published in Nature Metabolism reveals that marathon running causes a temporary reduction in brain myelin content. Inspired by his own experience completing 18 marathons, researcher Carlos Matute questioned how the brain adapts to such extreme physical exertion. He hypothesized that myelin, a fatty substance making up a large part of the brain, might be used as an emergency energy source during endurance events. The research shows that this myelin reduction is reversible, highlighting the brain’s remarkable ability to adapt and recover after intense physical challenges.