Physical activity increases blood flow to the brain, which might account for healthier cognitive function

BrainBlogger - Exercise to Keep Your Brain Healthy and Increase Cerebral Blood Flow

This blog post references a variety of studies, mostly relating to cognitive health and exercise. There is a long-standing correlation between exercise and cognitive function in older adults yet the mechanism was unclear. Using MRI and magnetic resonance angiography (MRA), scientists found increased blood flow to the brain and a greater number of small blood vessels in older adults who regularly exercised. The theory is similar to the rest of the body: these small blood vessels shrink and shrivel as we fail to pump blood through them, which aging and lack of exercise both do. Less blood flow to all the parts of the brain might be link. Most of this work was done regarding aerobic exercise, not weight or resistance training, though the latter kinds of training are good for older adults for other reasons, like staving off morbidity.