I’ve always claimed that I run as much for my mind as for my body. Running helps me “declutter” my brain, allows me to come up with solutions to problems that have been pestering me, facilitates creative thinking, and frees me of stress that would normally burden me. But I thought it basically ended there. Exercise kept both my brain and body young, flexible, and energetic.
I was intrigued, then, to see this headline in the New York Times: “How Inactivity Changes the Brain” — intrigued not because I thought it was particularly interesting, but because I thought everyone already knew that being active helps you think better and keeps your mind clearer. How could this possibly be news? was my real question. Certainly this was just another article telling us that exercise will help us think better.
But no. I was wrong. And the article — and the study that spawned it — is, indeed, intriguing. What happens when you have two sets of rats: one that runs three miles on a treadmill every day and another that is sedentary? What happens if after three months of either activity or inactivity, you check the development of their brains’ sympathetic nervous system — the part that controls unconscious things like breathing?
What you find, according to the study done by scientists at Wayne State University School of Medicine and published in the Journal of Comparative Neurology, is that the sedentary rats’ brains develop abnormally. Their sympathetic nervous system grows many more branches — too many. With so many branches, the neurons are much more sensitive and much more likely to misfire, causing things like increased blood pressure.
So, basically, we’re starting to see — through these test rats — on a very fundamental level the cellular changes that living a sedentary life probably leads to in our brains and what that means for the physical changes that happen in our bodies. And it’s not pretty. It is inefficient and ineffective, overcrowded and overstimulated. In contrast, it looks as though the “brain on exercise” is able to stay trim, efficient, and de-cluttered, just as the body on exercise is able to do.
It may not be the “sexiest” motivation for leading an active lifestyle (I find that attempting to solve the world’s — or at least my family’s — problems on my daily run is much more compelling), but it certainly does give better understanding of why our bodies develop so many problems if we don’t take care of them. And that, sexy or not, is an empowering thing to know.