Does Exercise Result in Brain Growth?

Is your cardio routine increasing the size of your cranium? A new study says it could

Credit: iStock / Fotosmurf03

According to researchers, regular exercisers may have larger mid-brains than more sedentary people

A new study suggests that getting more exercise may not only pump up your muscles, but your brain too

Over the years, I’ve had to spend far too much time in fitness centre changing rooms listening to men of a certain age go on and on about their athletic endeavours, such as, for example, riding in the Gran Fondo bike race, or their latest triathlon or marathon accomplishment.

But from all that forced listening (it’s very hard to get away from a guy who’s bent on bragging when all you have on are your shorts, and maybe not even that), I’ve become convinced that God plays a pretty mean joke on most of these boring braggarts.

You see, I believe that for all the inevitable growth those guys build up in their quads, abs, pecs, egos, etc., there is a compensatory shrinkage in some of their other perhaps even more important parts, like their senses of humour and their brains. Although I may now have to retract that bit about their smaller brain size.

Effects of Exercise on the Mid-brain

In a recent study from the University of California published online in The Journal of Experimental Biology, researchers examined the brains of mice that have been especially bred over 65 generations to be “exercise-loving.” That is, given their druthers, exercise-loving mice choose to run and run and run. According to the researchers, these mice have larger mid-brains than mice that are left alone to move only when they get the urge to eat or breed.

Now if you’re ready to dismiss this study because, like me, you don’t really give a damn about mice brains, you may want to think about this study’s implications again, especially if you don’t exercise regularly. According to the researchers, human exercisers may also have larger mid-brains than more sedentary people. And as the researchers point out, the mid-brain “is essential for reward learning, motivation and reinforcing behaviour.”

Opposition to the Study

Before you try to rouse yourself from your couch to start training for a 1K walk, please note several strong caveats to this report. First, there’s the common warning that a mouse is not a human, and many (perhaps most) results from studies done on mice have not been replicated in humans.

Also, even though they ended up with larger mid-brains, the overall brain size in the run-loving mice was not any larger on average.

And most importantly, I think, it’s not clear that a mouse that comes to running only in midlife (or later) would gain the same growth in brain size, a sobering thought for anyone who thinks they can increase the size of their brain just by starting to run at the age of 40 or 50.

In fact, I thought it over and decided I’d rather build a bigger brain by doing crosswords instead.

Dr. Art Hister is a medical writer and health analyst for Global TV.

Originally published in TVW. For daily programming updates and on-screen Entertainment news, subscribe to the free TVW e-newsletters, or purchase a subscription to the weekly magazine.