Most of us put the time and energy in at the gym because we want to get bigger—bigger muscles, bigger presence, and bigger orbit of attraction. That's all fine and well, but make sure to also get in your aerobic exercise; it's been shown to keep the brain bigger and healthier as you age—strengthening memory and helping to prevent neurodegenerative diseases like Alzheimer’s and dementia, says a new study.

The research appeared in the journal NeuroImage, and was performed by scientists at Western Sydney University in Australia and the University of Manchester in the U.K. Researchers checked out 14 previous studies that had taken a look at the brains of more than 700 people before and after aerobic exercises like spinning, walking, and running on a treadmill. Participants ranged from age 24 to 76, and their exercise periods went from three to 24 months and covered two to five sessions a week.

The results showed that the left region of the hippocampus, a part of the brain tasked with memory storage and spatial memory, was significantly larger in the aerobic exercisers.

"When you exercise, you produce a chemical called brain-derived neurotrophic factor which may help to prevent age-related decline by reducing the deterioration of the brain," said lead author research fellow at the National Institute of Complementary Medicine at Western Sydney University. "Our data showed that, rather than actually increasing the size of the hippocampus per se, the main 'brain benefits' are due to aerobic exercise slowing down the deterioration in brain size. In other words, exercise can be seen as a maintenance program for the brain."