Exercise and Long-term Brain Function

There's an article in today's NY Times Magazine titled "Jogging Your Brain." Here's the premise: long term brain atrophy is decreased through heart-rate elevating physical activity. The first study is with four sets of mice. Set one experiences no stimulation. Set two has mental stimulation (toys). Set three has mental stimulation and physical stimulation. Set four has only a running wheel. Sets three and four preserved brain capacity and performed on cognitive tests commensurately better. (Set four as much so as set three -- the added mental stimulation was irrelevant.) A study in older humans found decreased brain atrophy among the members of a set of walkers as compared with the members of a set of stretchers. Apparently the exercise elevates BDNF, "a substance that strengthens cells and axons, fortifies the connections among neurons and sparks neurogenesis" -- brain cell creation. I haven't run since Boston. No wonder I'm having trouble getting words on page. Heading out for 10 today. [By the way, am I the only one with a different blogger interface when creating a post? Among other indicia of weirdness, I can't create paragraphs in my text.]