Data from a publicly available database of 1206 MRI brain scans from the Human Connectome Project has revealed that physical fitness is associated with better brain structure and brain functioning in young adults.

A study in which 64 sedentary older adults (aged 60-88) participated in a 12-week exercise program found that those who engaged in high-intensity interval training (HIIT) saw an improvement of up to 30% in memory performance while participants who engaged in moderate-intensity aerobic exercise s

A study involving 30 previously physically inactive older adults (aged 61-88) found that a three-month exercise program reversed some brain atrophy.

A long-running study following 387 Australian women found that regular exercise in middle age was the best lifestyle change they could make to prevent cognitive decline in their later years.

Memories are made through a synaptic-strengthening process called

A Canadian study involving 45,522 adults (30+) found that higher levels of physical activity, eating more fruits and vegetables, and having a BMI in the normal weight or overweight range were each associated with better cognitive function in both younger and older adults.

A rat study comparing different forms of exercise has found that running was much more effective than HIIT or resistence training in generating new brain cells.

A large study, involving nearly 14,000 older adults (50+) participating in the 2006 Health and Retirement Study, found that weaker handgrip strength was associated with a greater risk of developing cognitive impairment, especially severe impairment, over the eight-year study period.