Exercise enhances and protects brain function.

@article{Cotman2002ExerciseEA,
  title={Exercise enhances and protects brain function.},
  author={Carl Cotman and Christie Engesser-Cesar},
  journal={Exercise and sport sciences reviews},
  year={2002},
  volume={30 2},
  pages={75-9}
}
Physical activity, in the form of voluntary wheel running, induces gene expression changes in the brain. Animals that exercise show an increase in brain-derived neurotrophic factor, a molecule that increases neuronal survival, enhances learning, and protects against cognitive decline. Microarray analysis of gene expression provides further support that exercise enhances and supports brain function.