CHICAGO (AP) -- A new study suggests that brisk walking can lead to slight improvements on mental tests for older people with memory problems.

Experts say it's the first rigorous test of its kind.

The results from the small Australian study were only modest and need to be duplicated in larger studies. But they back up previous observational research.

Participants did at least 2 1/2 hours of weekly exercise, mainly brisk walking, for six months. Then, the exercise group performed just over one point better on a 70-point scale of brain function than a control group.

Results are in this week's Journal of the American Medical Association.

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