Being more physically active is associated with having larger brain volume, a 2022 study found. The greatest brain-enhancing effects were seen in those who engaged in moderate- to vigorous-intensity exercises.

The study involved more than 2,500 adults between the ages of 30 and 94 years. The participants wore wrist accelerometers to track their activity levels and underwent brain scans to assess their brain volume, cortical thickness, and gray matter density.

The scans revealed that physical activity had a marked, dose-dependent effect on the participants' brain health. Those with greater, more intense physical activity levels exhibited larger brain volumes – especially in the hippocampus, an area of the brain involved in memory – than those with lower, less intense levels. However, the beneficial effects of physical activity on brain health were particularly evident when comparing the brain volumes of those who engaged in moderate physical activity to those who were sedentary, suggesting that even small increases in physical activity can boost brain health and reduce brain volume losses associated with aging.

The beneficial effects of physical activity may be related to exercise-induced production of brain-derived neurotrophic factor (BDNF), a protein that controls and promotes the growth of new neurons. BDNF is active in the hippocampus, cortex, cerebellum, and basal forebrain – areas involved in learning, long term memory, and executive function. Learn more about the brain-boosting effects of BDNF in our comprehensive overview article.

• Read study abstract.