Aerobic exercise can increase the size of the aging brain’s hippocampus, the part that houses memory and spatial navigation, researchers report in new study findings.

Researchers studied 120 older adults (ages 55 to 80) who didn’t normally exercise regularly, over the course of a year. Half of the group was assigned to an aerobic exercise program while the other half completed a stretching-and-weights program. Both groups received MRIs and performed spatial memory exercise. The group that did aerobic exercise for a year saw increases in hippocampus volume, while the stretching-and-weights group saw a decrease in hippocampus volume.

“We demonstrate that loss of hippocampal volume in late adulthood is not inevitable and can be reversed with moderate-intensity exercise,” researchers wrote. “Starting an exercise regimen later in life is not futile for either enhancing cognition or augmenting brain volume.” The study was published in the journal Proceedings of the National Academy of Sciences.