I think the "changes our DNA" is far fetched, but the link between exercise and the neurochemistry in the brain has been proved by multiple studies. I've menti

I think the "changes our DNA" is far fetched, but the link between exercise and the neurochemistry in the brain has been proved by multiple studies. I've mentioned here before, but John J. Ratey recently wrote the excellent Spark: The Revolutionary New Science of Exercise and the Brain[1], where he explains in colorful details what happens in (and to) the brain when you exercise. [1] http://www.amazon.com/Spark-Revolutionary-Science-Exercise-Brain/dp/0316113514 http://www.amazon.com/Spark-Revolutionary-Science-Exercise-B...