I read a great book recently called Brain Rules, by John Medina. It talks about how brain science has proven some simple truths about the way we learn and interact in the world and what we should be doing differently to maximize our school system and our work environment for productivity.
I was surprised that Brain Rule Numero Uno was: EXERCISE!! I was hooked immediately, can you imagine why? Basically this chapter talked about the fact that Homo Sapiens evolved from nomadic tribes that would have to walk at least 12 miles a day, and therefore the brain evolved to be most productive when being stimulated by physical activity.
We are not wired to be able to sit for 8 hours straight without moving and still be productive - or even stay interested in what we are doing! That is why it's astonishing that so many of our office jobs require us to do just that. It is also equally ironic that when schools begin to lose ground on test scores, one of the first things to get cut is recess. The truth is we need miniature breaks in our day to walk and move around. For a long time I have found time to do some pushups, pullups, or burpees while at work, and for a long time I actually did my P90X AT work during the middle of the day, and little did I know how beneficial this was to my productivity. The author even advocates having a treadmill in your office so you can read and do computer work while walking at a slow pace. Wouldn't that just be revolutionary!
Another part of this equation is that exercise brings more blood to your brain, thus improving its function. The book described even the very interesting process of how exercise helps remove toxins from our blood and actually makes the blood vessel pathways throughout the whole body wider and easier to transport blood. Did you know that when food is digested and it is broken down into molecules of the glucose for absorption, the reaction is so violent in your digestive system that it is similar to a nuclear reaction? Literally the byproduct of this violent reaction is a "free radical" which we have always heard so much about. Our body is constantly working to get rid of these free radicals, but when you exercise you speed up this process by increasing blood flow and oxygen. Exercise also supposedly stimulates the protein that keeps your neurons connecting. This can help with memory and speed at completing tasks.
Finally, and perhaps the most intriguing part, is that studies show exercising only twice a week nearly halves the risk of dementia in old age and reduces your chance of getting Alzheimer's by 60%. There are the hard studies, and also anecdotal evidence, like the fact that Jack Lalanne was sharp as a nail even in his final days in his late 90s.
So, you always knew working out was good for you, but I bet you never knew how good it was for your brain! That was just a basic summary of the chapter, I highly encourage you to pick up the book and read it for yourself. Also, I believe you can preview that very first chapter on Kindle if you want to just read it for free on your device.