Aerobic Exercise and Your Executive Brain

June 13, 2011

Aerobic Exercise and Your Executive Brain 

 Reference:  American College of Sports Medicine Congress, June 10th, 2011 Denver 

 Use it or lose it!  Very simple.  As we age, the slope and velocity of our deterioration increases. We have a voice and control over just how much we let ourselves go.  The secret is aerobic exercise, aka: sweat.  And this study shows the details. Up till now, we have known that brain structure and function deteriorate with age.  Your brain shrinks.  We’ve said that’s normal.  Well, it is because most of us let it happen.  Because most of us let it happen, is it really normal?  

The real question is:  is it inevitable?  It is reversible?  Surely, we all know very old men and women who are perfectly intact brains and who show no cognitive decline.  How did they do it? Dr. Tseng of the Exercise and Environmental Medicine Cerebrovascular Lab at Texas Health Presbyterian Hospital in Dallas followed 10 Master Athletes, average ages of 73, who had been exercising rigorously for at least 15 years and compared their brains to matched controls of similar ages who were couch potatoes.  Normal, older American men.  

What they found was that WHITE matter (not gray matter) was much better preserved in the athletes.  White matter is all the wiring beneath the grey matter that connects all the parts of the brain to each other.  You have parts in your brain that are discretely assigned to vision, to speech, to hearing, memory and emotions.  That’s all part of grey matter.  Those discrete brain regions have to talk to each other in complex fashions.  And quickly.  To be fast, you have to be hooked up.  

You can measure the speed of a young person’s brain responding to a sound impulse in their ear.  A young brain lights up with recognition in about 310 msecs at age 20.  Nice and fast.  By age 50, the response time is 350 msec.  Oops.  40 msec gone.  Can’t remember the checkbook whereabouts.  By 380 msec, you have Alzheimer’s.  All a matter of 20-30 msec of processing speed. That is the difference between a functioning 50-year-old who sits and ponders for a second to remember “that person’s name”, or “the restaurant we went to that time…” and dementia. It’s the wires in between that keep you younger.  

Magic Bullet #2 is exercise.   It preserves your wiring better than anything else yet discovered.  We’ve known for years that a mere walking 30 minutes a day for 6 months will show measurable improvement in memory that will last for up to 18 months after stopping.  That’s just walking.  Now, speed it up, and speed your brain up.  There is no other way.  Getting sweaty. 

 WWW:  What Will Work for me.  I’ve got a million excuses.  My best ones I can’t remember.  But I’m now spooked enough by my own failings and frailties.  I’ve forgotten enough appointments, enough reminders to bring home milk to no longer find it easy to ignore.  I’m trying to walk every day.   I need friends to encourage, to remind, to cajole, to support me, and ask me when I last got enough exercise to be sweaty.  Running a mile, that’s my first goal.  Tennis anyone? Over age 60, getting sweaty is job One for anyone interested in keeping themselves alert, independent, functioning, and in relationship.

This column was written by John E. Whitcomb, MD, Brookfield Longevity, Brookfield, WI