Changes in the Brain  

In this context, physical exercise refers to planned aerobic activity or resistance training. Physical exercise is something that is very important to the human body. For example, the best way to imagine the body is to think of it as a machine; all the pieces must be intact, maintained properly, and used correctly in order for it to function properly. 

When comparing the body to a machine, the similarities would be as follows: organs are the parts, the brain is the operating system, food is the fuel source, and physical exercise would be the maintenance. With that being said, in order for the brain (operator) to properly control the organs (machine parts), the food a person ingests (fuel), and physical exercise (maintenance) are necessary for optimal conditions of the body and can even speed up how the brain and other organs work.

Some of the evidence that has been published by leading scientists within the field is very convincing. The studies have been performed on various animals, specifically rats  and humans. During a study conducted by Leuner and Gould they proved that the long-term potential (LTP) phenomena was in fact true, but only for a select region of the brain known as the hippocampus (2010). The LTP phenomenon is when there is an increase in the long-term connection between neurons through their synapses. In layman's terms, this means that exercise can indirectly make synapses more efficient. Within the study, a correlation was found between rats that were randomly assigned to one of two groups: the exercise group (experimental group), which had substantially high LTP, and the non-exercise group (control group), which had significantly lower LTP levels. Another important chemical that is released during physical exercise which has been correlated to more efficient synapses is brain-derived neurotrophic factor (BDNF). This neurotrophin is involved in many chemical processes that support brain plasticity, especially in the hippocampus. A study conducted on humans by Yarrow, White, Mccoy and Borst concluded that there was a 32% and 77% change in BDNF that was observed at baseline and post-intervention (2010).