Exercise Improves Brain Performance
We often think that working out only makes our muscles stronger or our heart and lungs more efficient. But in fact one of the biggest benefits of exercise that it makes our brains work and perform better and more efficient. If you look at the human body as a whole this is not all that surprising. In fact your brain uses the most energy out of any other organ in your body so when you can increase your heart and lung capacity, your brain will automatically benefit. This is especially true for kids and teenagers since their cognative abilities are still growing. So if you want to be smarter, go for a run or start lifting weights because your brain, and whole body, will thank you!
Source: http://www.brainhq.com/brain-resources/everyday-brain-fitness/physical-exercise