April 23, 2012 (CHICAGO) --When it comes to exercise and healthy brains, pumping iron may be something more women should consider. A new study in this week's "Archives of Internal Medicine" is adding to evidence that a work out can help fight off dementia. Researchers studied 86 women with signs of mild cognitive impairment. They were divided up into groups to do different exercises for six months. Those who did resistance training including weights two times a week did better on cognitive tests. Special imaging showed that brain plasticity was improved in key regions of the brain, meaning part of the brain was able to compensate for any changes.