How walking benefits the brain

Until recently, the blood supply to the brain (cerebral blood flow) was thought to be involuntarily regulated by the body and relatively unaffected by changes in blood pressure caused by exercise or exertion.

The researchers behind this study have previously found that the foot’s impact during running (which is around 4-5 G-forces) caused significant impact-related retrograde (backward-flowing) waves through the arteries. These sync with the heart rate and stride rate to dynamically regulate blood circulation to the brain.

Regulating blood flow

For their current work the team used non-invasive ultrasound to measure internal carotid artery blood velocity waves and arterial diameters in 12 healthy young adults during standing upright rest and steady walking (1 meter/second). This allowed them to calculate cerebral blood flow to both sides of the brain.

Although there is lighter foot impact associated with walking compared with running, walking still produces larger pressure waves in the body that significantly increase blood flow to the brain.

While the effects of walking on cerebral blood flow were less dramatic than those caused by running, they were greater than the effects seen during cycling, which involves no foot impact at all.

“New data now strongly suggest that brain blood flow is very dynamic and depends directly on cyclic aortic pressures that interact with retrograde pressure pulses from foot impacts,” the researchers wrote.

They add that there is a “continuum of hemodynamic effects on human brain blood flow within pedaling, walking and running” and that by increasing blood flow to the brain each of these activities can add to the overall sense of wellbeing that many people feel when doing thees activities.

“What is surprising is that it took so long for us to finally measure these obvious hydraulic effects on cerebral blood flow,” comments first author Ernest Greene.