Exercise increases your intelligence

It has long been known that children who are physically active during school hours get better grades, have fewer conflicts and socialize better. New research led by Maria Åberg from the University of Gothenburg has shown that those who are physically active are smarter than those who do not exercise. In fact, those who exercise a lot are smarter than those who exercise less. Since the experiments were carried out on twins, the research team knows that it is the exercise that increases intelligence and not other factors. This is probably because exercise increases a substance in the brain, BDNF, which is a growth hormone that increases the size of the hippocampus. The bigger the hippocampus, the better our memory.

http://www.pnas.org/content/early/2009/11/25/0905307106.abstract