Scientists at Penn State have discovered that contracting your abdominal muscles — even slightly — causes your brain to shift gently inside the skull. This motion, transmitted through a network of veins connecting the abdomen to the spine, helps circulate cerebrospinal fluid around the brain. That fluid movement is believed to flush out metabolic waste linked to neurodegenerative diseases like Alzheimer's. Published in Nature Neuroscience, the study used mouse imaging and computer simulations to confirm the mechanism. Remarkably, even low-level pressure — less than what a blood pressure cuff applies — was enough to trigger brain movement. The findings offer a new mechanical explanation for why regular physical activity protects brain health over a lifetime.
