Prolonged reduction in physical movement impairs the hydraulic clearance of metabolic waste from the brain, resulting in accumulation of metabolic waste and contributing to brain fog and long-term cognitive decline.

Study: Increased sedentary behavior is associated with neurodegeneration and worse cognition in older adults over a 7‐year period despite high levels of physical activity

People who sit a lot, even if they exercise, tend to lose brain volume faster and think more slowly over time — suggesting that sitting may interfere with the brain’s natural cleaning process.

Study: Effect of organismal rhythmic activity on Aβ clearance by the glymphatic system

When you move less—like when sitting all day—your brain’s cleaning system works worse. The study shows that activities like exercise and deep sleep help the brain flush out toxins, and when those movements stop, the cleaning drops a lot.

Study: Intrinsic mechanical vibrations as a missing dimension in amyloid-β clearance: a mechanochemical hypothesis for Alzheimer’s disease

When you move your head and neck—like when you hum or talk—it creates tiny vibrations that help your brain flush out trash. Sitting still too long might stop those vibrations, so the trash builds up and makes you feel foggy.