Study investigates how running a marathon impacts brain health

September 15, 2025

Marathoners hear plenty of scary claims about what running 26.2 miles can do to the brain. A new open access study paints a clearer, calmer picture.

Exercise research over the past two decades has consistently linked regular activity with sharper attention, memory, and learning. This foundational review summarizes how aerobic training supports brain networks and key molecular pathways that help the brain adapt.

The work was led by Carlos Matute, professor of neurosciences at the University of the Basque Country (EUH).

Researchers scanned 10 runners ages 45 to 73 with advanced MRI both 24 to 48 hours before and after a marathon, then again for subsets at two weeks and two months.

They focused on myelin water fraction (MWF), an MRI signal that tracks water trapped within the myelin layers that insulate nerve fibers.

MWF is widely used as an in vivo marker for myelin content, with good agreement to tissue studies. It is sensitive to subtle shifts that may not show up on standard brain scans. earth