Likely, you have already read or heard about the importance of remaining active to stave off the onset of Alzheimer's disease. The term "stay active" can take on several meanings and lend itself to varied interpretations. So, how exactly does one stay active? 

By keeping the brain active. 

Research has shown that age-related mental decline occurs as the result of changed or lost connections between cells in the brain. Continued neural activity helps the brain maintain these vital pathways between its cells, and it even helps to encourage the creation of new brain cells. Neural activity is most effectively increased or maintained by staying active in three key ways.

1. Mentally - Treat the brain to a daily workout by solving puzzles, trying out a new hobby, or learning a language or skill. Challenging the brain mentally will maintain the connections made between brain cells which are important to learning and reasoning. 
2. Physically - Several parts of the brain control the body's movement including the motor cortex, neurons located in the brainstem and midbrain, the cerebellum, thalamus, and basal ganglia. Participating in physical activities such as walking, gentle yoga, or tai chi will exercise these portions of the brain. Learning a new physical activity will activate both physically-involved portions of the brain as well those responsible for learning and memory. In addition, aerobic exercise increases oxygen levels throughout the body, stimulating the brain.
3. Socially - Remaining socially active in conjunction with mental and physical activity has been shown to further reduce the chances of developing Alzheimer's disease. Social activities which involve physical or mental elements like group exercise, classes, and volunteer organizations provide great opportunity to stay socially active. 

While mental, physical, and social activity each contributes to the brain's vitality, they are most effective together.