Over the years numerous studies have shown that exercise not only improves our overall health, but also our memory and cognitive skills as a whole. How is this exactly?
Neuroscientists have figured out that the strength of our synapses is dependent on how we live our lives. Between sleep, diet, stress, and more, the stronger the connections, the stronger our memories and cognitive function. Not surprisingly, dementia/Alzheimers is a product from changes of energy usage in our brain cells. A study published by Nature Medicine explained how exercise protects our brains on a molecular level through the hormone irisin. Irisin is a hormone secreted in our muscles to the brain during exercise that starts biochemical reactions related to energy metabolism. Analyses of diseased and normal brain tissues taken from brain banks showed low to nonexistent concentrations of irisin in those who died with dementia and vice versa. However, scientists looked to mice for more information.
Mice bred with dementia were injected with irisin and performed better on memory tests than healthy mice injected with a beta amyloid inhibitor (creating dementia). Their synapses functions were mirror images to their performance during the tests. A more important test involving direct exercise: mice worked out for 5 weeks (running and swimming) with some mice injected with the inhibitor before hand. The healthy mice performed well on memory tests even after being exposed to the inhibitor post workout. However, the previously effected mice performed just as badly on the tests as the dementia effected mice from the experiment before.
Researchers are not 100% sure how much irisin effects humans, but know enough based off of their experience with lab mice, that exercise plays a prominent role is fighting or postponing dementia/Alzheimers.
Opinion: I find it amazing that irisin was not found until 2012 and we are just figuring out that maybe around 30 minutes of daily exercise is not just good for loosing weight, but cognitive function. Hopefully more research on humans is done soon, so we can all stay active for better reasons. This might even push the middle school kids harder during gym class.