Lifting weights can do more than pump up your muscles. It may also slow the age-related shrinking of some parts of the brain.

Recently published research by Canadian scientists found that light resistance training reduced shrinking and tattering of the brain’s white matter. The white matter is crucial to passing messages between parts of the brain, but it’s also vulnerable to developing holes and lesions beginning in late middle age.

Medical experts already knew that aerobic exercise could help preserve the brain’s white matter. Researchers wondered if weight training could also help.

Researchers tested walking speed and agility in a group of 54 women between the ages of 65 and 75. They were divided into three groups, with one group doing light weight training once a week. Another group did light weight training twice a week. The third group did only stretching and balance training.

After a year, the subjects had a brain scan and re-tested their walking ability. The findings, published in the Journal of the American Geriatrics Society, were stark. The women who did no weight training had a diminished walking ability as well as more and larger lesions in their brain’s white matter. Those who did weight training once per week had similar results.

But here’s the good news: The women who lifted weights twice a week had less shrinkage of their brain’s white matter. They also walked faster and more smoothly than those in the other two groups.

Researchers said this apparently shows that weight training can help preserve brain structure, as long as a minimum exercise threshold is met. That probably means doing some resistance training at least twice a week.

That’s just another incentive to hit the gym.