How exercise increases brain volume — and may slow memory decline

Exercising for 25 minutes a week, or less than four minutes a day, could help to bulk up our brains and improve our ability to think as we grow older.

A new study, which involved scanning the brains of more than 10,000 healthy men and women from ages 18 to 97, found that those who walked, swam, cycled or otherwise worked out moderately for 25 minutes a week had bigger brains than those who didn’t, whatever their ages.