Science Wednesday: This is your brain on exercise.

It’s Science Wednesday at Every48 – my once-a-week opportunity to share with you study findings, thoughts from big thinkers, or other literature in the big wide world of exercise and health science to learn more about what actually happens to our bodies when we live an active life.

This is your brain. Really. Add a prefrontal cortex and you've got a human. (Image courtesy of AKARAKINGDOMS /
This is your brain. Really. Add a prefrontal cortex and you’ve got a human. (Image courtesy of AKARAKINGDOMS /

Today’s installment comes from the world of rat research. (I’m working on a writing project right now that has offered the opportunity to interview some very brilliant folks in the world of obesity and diabetes research – and one of them came up with the perfect explanation of why we see rat research done by investigators who want to study the human brain. Basically, rats are people without the prefrontal cortex. Behind that little rascal, we’re wired up just about the same way as your friendly neighborhood rat. I’m not sure that’s the most comforting thought I can offer you today, but I just thought you’d like to know.)

Okay, back to Science Wednesday. The big takeaway – from a study published in February 2014 in the Journal of Comparative Neurology – is that regular physical activity (for rats, that would be running on a wheel in their cages) has a positive effect on the sympathetic nervous system. Active rats were less likely to overstimulate the part of the brain that constricts blood vessels, which suggests that there could be a positive association in the brain between regular physical activity, and a reduction in heart disease risk.

In Gretchen Reynolds’ report on the study in the New York Times, she writes:

A well-regulated sympathetic nervous system correctly directs blood vessels to widen or contract as needed and blood to flow, so that you can, say, scurry away from a predator or rise from your office chair without fainting. But an overly responsive sympathetic nervous system is problematic, said Patrick Mueller, an associate professor of physiology at Wayne State University who oversaw the new study. Recent science shows that “overactivity of the sympathetic nervous system contributes to cardiovascular disease,” he said, by stimulating blood vessels to constrict too much, too little or too often, leading to high blood pressure and cardiovascular damage.

Exercise science is coming up with new ideas all the time about how regular activity puts us at less risk for heart disease (the leading cause of death in the United States, by the way).  We know about the ways in which regular exercise keeps our arteries and capillaries healthy, and our circulation humming…but this study was seriously fascinating because it’s looking like exercise may have a positive effect not only on the nuts and bolts of our circulatory system, but also on the brain’s ability to monitor the sympathetic nervous system and its functions.

And that’s just another reason to get out there and get your workout on.

Yesterday’s #Every48 workout: I confess to having fallen into the “injury trap” – I’m nursing what’s turned out to be a knee injury that just needs rest and strengthening, but no running, for a few weeks, and I was bummed out yesterday and didn’t get to the gym for my swim. (I could bike, too, or lift weights, or all three…the only thing I can’t do right now is run.) It is so easy to feel sorry for myself with these things – “poor me, I can’t do the one thing I love to do, so I’ll just…have too much pizza at a work event and then top it off with frozen yogurt at 10 p.m.” Yikes. There, I copped to it. Today shall be different – I pinky-swear ya.


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