In Women, Training for a Sharper Mind

In particular, older women and strength training:

Older women who did an hour or two of strength training exercises each week had improved cognitive function a year later, scoring higher on tests of the brain processes responsible for planning and executing tasks, a new study has found.
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A year later, the women who did strength training had improved their performance on tests of so-called executive function by 10.9 percent to 12.6 percent, while those assigned to balance and toning exercises experienced a slight deterioration — 0.5 percent. The improvements in the strength training group included an enhanced ability to make decisions, resolve conflicts and focus on subjects without being distracted by competing stimuli.