A recent study published in Nature Neuroscience suggests that the brain is more mechanically connected to the body than previously appreciated. Scientists found that abdominal muscle contractions compress blood vessels connected to the spine and brain, pushing fluid that gently moves the brain within the skull. This physical swaying provides evidence for how exercise might benefit brain health by washing away cellular waste.

Scientists set out to understand the specific mechanical origins of brain motion in awake animals. The central nervous system is encased in thick bone, making it seem isolated from the physical forces of the rest of the body. However, the work builds on previous studies detailing how sleep and neuron loss can influence how and when cerebrospinal fluid flushes through the brain, according to Patrick Drew, a professor of engineering science and mechanics, neurosurgery, biology and biomedical engineering at Penn State.

“Our research explains how just moving around might serve as an important physiological mechanism promoting brain health,” said Drew, corresponding author on the paper. “In this study, we found that when the abdominal muscles contract, they push blood from the abdomen into the spinal cord, just like in a hydraulic system, applying pressure to the brain and making it move.”