Normally, the hippocampus—a part of the brain important in forming memories—begins to deteriorate when healthy adults reach age 55 or 60. But psychologists suggested that adults can increase the size of this brain area simply by taking regular walks, according to a study published in The Proceedings of the National Academy of Sciences.

For the one-year study, researchers randomly assigned 120 participants in their mid-60s to one of two exercise groups; one group walked for 40 minutes around a track three times each week, and the other group did a variety of exercises that were less aerobic including yoga and resistance training with bands.

At the end of the study, brain scans of the walkers showed the hippocampus increased in volume by almost 2 percent on average. In contrast, non-walkers showed a hippocampus shrinkage of about 1.4 percent. In addition, although both groups improved on a test of spatial memory (how the brain stores information about the location of physical objects), walkers showed the most improvement.

While the results can’t be generalized to other populations, researchers concluded that even just a little exercise could expand the hippocampus. And people didn’t even have to join a gym to do so, noted Kirk Erickson, PhD, PsyD, a psychologist at the University of Pittsburgh.

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