Walking and other simple body movements can promote fluid circulation in the brain and potentially help it get rid of metabolic waste products, according to a study published in Nature Neuroscience.
A team of scientists studied brain movement in awake mice using high-speed two-photon microscopy. The researchers found that during movement, the brain shifts slightly within the skull, a process that is closely linked not to breathing or heart rate, but to the contraction of abdominal muscles during movement.
According to the authors of the paper, the contraction of the abdominal muscles creates mechanical pressure, which is transmitted to the brain through the vascular connections between the abdomen, spine and central nervous system. Scientists describe this mechanism as a kind of “hydraulic” coupling: body movement and muscle tension can trigger micro-movements of the brain and influence the movement of cerebrospinal and intercellular fluid.
Modelling has shown that such gentle brain movement can promote the removal of intercellular fluid from brain tissue into the subarachnoid space. The authors emphasise that the direction of this flow is different from that observed during sleep, when the so-called glymphatic system, associated with clearing the brain of metabolic products, is more active.
The popular science publication ScienceDaily, referring to this study, notes that the contraction of abdominal muscles during movement can contribute to the circulation of cerebrospinal fluid, and therefore, simple physical activity could potentially be associated with maintaining brain health. One of the authors of the paper, Patrick Drew, explained that body movement may be an important physiological mechanism that affects the brain through mechanical connection to the abdomen.
That said, the study does not prove that walking directly “clears” the human brain or treats neurological diseases. The work was done on mice, and the results on humans require more research. However, it shows a possible biological mechanism by which regular motor activity may be beneficial not only for the heart, blood vessels and muscles, but also for the fluid metabolism processes in the brain.
For the medical and wellness market, this is important because walking remains one of the most accessible ways to maintain health. Unlike complex workouts, it does not require equipment, specialised conditions or high levels of fitness. If future research confirms a similar mechanism in humans, regular walking may gain another scientific explanation as a tool to prevent cognitive exhaustion and maintain normal brain function.
The study also states that brain movement during walking has a very small amplitude – we are talking about microscopic shifts that cannot be felt. However, it is these mechanical vibrations that can be enough to affect the movement of fluid in brain tissue.
A key finding of the work is that the brain is not completely isolated from the rest of the body, as has often been previously imagined. It is mechanically linked to body movements, and contractions of the abdominal muscles during walking and other activity may be part of a system that helps move fluids in and around the brain.