There may be more even more proof that what's good for your heart is also good for your brain. A new study finds young adults who run, or do other cardiovascular fitness activities, may also be preserving their memory and thinking skills in middle age.

University of Minnesota researchers studied nearly 3,000 people. Their average age was 25 when the study began. All of them underwent a treadmill stress test during the first year of the study and then again 20 years later.

Results show those who performed better during the treadmill test the second time around also did better on tests of their memory and thinking skills.

"The best thing for your mind is your body. That individuals who are physically fit are more likely to perform better in their cognitive function than those people who are less physically fit," explained Dr. Stephen Rao who researches Alzheimer's at Cleveland Clinic.

Researchers at the University of Minnesota hope to be able to use the tests to better identify people who may be more at risk of developing dementia. Rao says the bottom line appears to be physical activity aids brain health.

"We don't know exactly what the physical fitness elements are but it seems to imply that those exercises that involve some aerobic aspects to them are better for the brain than those that are not aerobic," he said.

Complete findings for this study are in the journal Neurology.