Why Training Should Be Called “Braining” (Part 2)

Monday, March 29th, 2010

If you’re reading this, likely you are smart enough to exercise regularly.  But did you know that you can flip that around, and that exercising regularly can actually make you smarter?  In Part 1 last week, we looked at how the neural components of physical activity could help us train and rehabilitate parts of our physical selves that aren’t necessarily involved in the actual exercising.  This week let’s look at how getting physical can keep us from going mental. {wink} There are a good number of studies on the effect of using mental exercise to enhance cognitive functioning.  But it turns out that research is demonstrating that “being a musclehead” might actually be intelligence-enhancing, and not just good for your heart, lungs, and appearance.  If you’re like me, and the idea of your mind checking out on you one day already makes you want to start color-coding things and leaving yourself how-to notes (“Heath, put on panties then pants”), pay attention. 

                Physical exercise causes the release of neurotransmitters such as serotonin and dopamine—pleasure chemicals that give us the euphoria we seek, and sometimes do exercise exclusively for some days.  (Anyone else use their sweat sessions as Prozac?  Thought so.)  I’m pretty sure you knew that, or something about it, whether intellectually or intuitively.  But these same chemicals give you focus as well.  They allow you to perform better all the way around, not just physically.  But don’t overdo—this has limiting returns.  For example, I read about one study that tested subjects on cognitive tasks (verbal memory, motor processing, visual memory, reaction times), then split the group into exercisers and non-exercisers.  The exercisers were put through a VO2 max test protocol, the non-exercisers weren’t.  I’m not sure who got the raw deal there. Then all subjects were to redo the cognitive tests.  There was no difference in any of the types of tasks between groups but one: verbal memory.  The exercisers did very poorly post-VO2 max test when compared to the non-exercisers.  And the effect lasted a few days!  The take home point?  Some exercise is great and has been shown to enhance overall cognitive functioning at the chemical level.  But trying to learn something requiring recollection of verbally delivered info after an exercise bout that sends you to the barf-bucket isn’t recommended.  I only felt it responsible to report that because I knew about it and some of you might have been planning to attend an important lecture right after a max effort.  But now, on to the useful stuff that talks all about how our exercise payoff is WAY more than skin deep.  It’s skull deep! 

                First you should know that most research (actually, all that I saw) touts aerobic exercise, and most often running, as the go-to brain boosting form of exercise.  So all you predominantly endurance training types should be friggin’ geniuses by now, and here’s why!  A 2006 study showed that after 6 months of aerobic training (vs. the “stretching and toning” group) the aerobic subjects were more dense… in a good way!  They had significant increases in volume in the frontal and temporal areas of their brains.  These areas are involved with memory, planning, behavior control, and other cognitive processes.  They didn’t dissect the subjects’ brains (can you imagine the disclaimer on that participant release form?), but it has been extrapolated from animal research that the volume increase is due to increased vascular and neural connections.  Considering that most aging-related brain function deficits are either vascular, neural, or both—this is a biggie for any of us who plan to rock it into our 80’s, 90’s, and beyond.  And KNOW we’re rocking it.  Or, heck, at least remember that we rocked it at some point.  

                We could stop there, mentally high-five ourselves, and head out for a nice trail run to get even smarter (and smugger, heh heh).  But here’s a little deeper tidbit.  As mentioned above, not only does exercise release neurotransmitters that alleviate both physical and mental pain, but it also causes the generation of new neurons.  Specifically this occurs in the hippocampus, the center of learning and memory in the brain.  It is theorized that the stress of exercise leads, through a series of pathways, to the creation of Brain-Derived Neurotrophic Factor (BDNF), a protein that leads to neurogenesis.  This is a protective response to the stress, not only to create new neurons but to also armor existing ones, thus keeping transmission signals in that part of the brain happening efficiently.  A two-fer–cool!  But wait, there’s more.  BDNF, ever the multi-tasker, also has reparative effects.  Research also showed that exercising mice regenerated more nerve tissue post-injury than non-exercising ones*.   This is huge for those of us who didn’t pack it in at 30, or don’t plan to, since humans lose brain tissue starting at approximately that age.  Eek.  But before you throw a note up on all your social networks like: “Closing my account, guys.  I’m hitting the treadmill indefinitely!”, you should know that they also found that mice bred to overexercise (what the…?) actually showed an inability to learn.  Apparently their BDNF levels increased to a point, then leveled out and didn’t respond to exercise.  Similarly, this has been observed in humans where a study showed that 60-75 year olds showed cognitive function improvements post-exercise training whereas 18-24 year olds did not.  The younger group, you see, had not had time to lose cognitive function yet, so there was less room for improvement.  The take home points there?  1) You CAN teach an old dog (person, mouse, etc) new tricks.  Or at least help them improve at old ones.; 2) You can’t sweat your way to mega-brainiac status.  (Rats.)

                Some final caveats, thoughts, and musings.  In the beginning I alluded to the pleasurable brain chemicals that we experience a boost in through exercise.  Nothing new there, and most of us know that exercise is one of the top natural “treatments” for depression and anxiety because of it.  But a commenter or two along the way in my reading made the point that the subjects in the studies who showed improvement in their mental and emotional condition were already different from other potential subjects because they at least had the motivation to seek the study out in order to participate in it.  Interesting.  And then there was a discussion of why exercise was not actually addictive (contrary to how some of you might think or act, LOL), in spite of the binding capacity that the aforementioned brain chemicals have to opioid receptors, like morphine and heroin do.  The thought there is that these chemicals aren’t released until 30 minutes into an exercise session, and, unlike other addictions, there’s a certain amount of discomfort involved before the ecstasy kicks in.  In a world that seems intolerant of anything non-instant—particularly gratification—this could explain why exercise has yet to become habit-forming with most of the American culture.  Pity.  There’s that motivation thing again.  And lastly, did you know that it’s also been proven that your brain can pull a maneuver of inducing fatigue when exercise is anticipated in an effort to maintain homeostasis?  I knew it! That explains why I can be all perky, starting to wind down a work day, all ready to do a fun workout, and… suddenly the yawns hit and all I want to do is nap. (So annoying. Please tell me I’m not alone.)  

So, while it’s clear that science is on to something with this “exercise = smarts” thing, perhaps just being inclined to seek out an activity, and consciously override the mysterious onset of pre-exercise ennui, AND keep going past the pre-gratification painful part, is what really makes exercisers “smart”. 

References:

http://www.webmd.com/fitness-exercise/guide/train-your-brain-with-exercise

http://serendip.brynmawr.edu/bb/neuro/neuro05/web2/mmcgovern.html

http://www.sharpbrains.com/blog/2008/06/26/physical-exercise-and-brain-health/

*For some reason I’m compelled to say that, personally, I’m not in support of this kind of animal research.  I’m sure the mice injuries were not exactly humanely induced, or the result of some convenient accidents the mice had during the course of the study, like “Oh look, Whiskers tripped over the water dish again.  Let’s use it!” But the information is here, so I’m using it.  Even though now I’m going to spend all night worried about my karma.  One of the perils of digging around for info about the body and how it works.