From Live Science:
A new study proves the old Roman saying, "A sound mind in a sound body" — the more fit one's heart is, the more one's brain seems to benefit, scientists now find.
Many earlier studies have linked physical exercise with brainpower in humans and animals, but most of the research in people focused on children or older adults. The few studies of young adulthood — when the brain changes rapidly, establishing many traits linked with intelligence — have yielded ambiguous data.
Read more ....