Why exercise boosts brainpower

A news article today shows why exercise boosts brainpower. Apparently, physical activity helps build new brain cells in the dentate gyrus, a region of the hippocampus linked with memory and memory loss. Here's an excerpt:

The researchers used magnetic resonance imaging scans to help document the process in mice—and then used MRIs to look at the brains of people before and after exercise. They found the same patterns, which suggests that people also grow new brain cells when they exercise.... Exercise generated blood flow to the dentate gyrus of the people, and the more fit a person got, the more blood flow the MRI detected, the researchers found. "The remarkable similarities between the exercise-induced cerebral blood volume changes in the hippocampal formation of mice and humans suggest that the effect is mediated by similar mechanisms," researchers said.