Use It or Lose It!

By Peter Holmes

                 We are all familiar with this term as it relates to fitness but few know that it can also apply to our brain. Our muscles respond to how much or how little we use them. If you have ever broken a bone in your arm or leg that was put in a cast for 6 to 8 weeks then you have firsthand experience with this phenomenon. When the cast was finally removed your cast arm or leg was visibly smaller than its counterpart. The injured limb is smaller and weaker due to a condition called Disuse Muscular Atrophy.

Our bodies are masters at conserving resources. Because you could not use the injured arm, your brain decided you no longer need as much muscle there so it redirected resources to other places that were being used. The converse is also true. If you challenge your muscles by physical activity the body adapts by getting stronger. As long as you keep doing the same routine you will maintain the strength and ability to lift the weight or cover the distance. Stop for awhile – and guess what – you will start to lose that capability to perform.

Our brains operate under the same ‘use it or lose it’ principle. One of the consequences of aging is that our brain actually shrinks in size; it gets visibly smaller. “Starting at about age forty, we lose on average 5 percent of our overall brain volume per decade, up until about age seventy, when any number of conditions can accelerate the process,” says John Ratey, author of Spark:  The Revolutionary New Science of Exercise and the Brain.  According to the Centers for Disease Control (CDC) the average seventy-five year old suffers from three chronic medical conditions and takes five prescription medicines. People who are obese are twice as likely to suffer from dementia and those with heart disease are at far greater risk of developing Alzheimer’s.

The mind and the body, or rather the brain and the body, are inseparably connected. What affects one impacts the other. Running keeps your heart and lungs healthy but it also keeps the capillaries in the brain from collapsing or corroding and causing a stroke.

Exercise protects our brains as much as our bodies. Research on depression has shown chronic depression shrinks certain areas of the brain. Exercise unleashes a cascade of neurochemicals and growth factors that can reverse this process. In Britain, doctors use exercise as a first-line treatment for depression. Researchers from Duke University pitted exercise against an anti-depressant (Zoloft) in a sixteen-week trial. The conclusion:  exercise was as effective as medication in reducing depression.

Why does exercise have this profound effect on our brains? It all goes back to the brain’s main function – survival. In our evolutionary history our brains grew and adapted to ensure our survival. We had to find the food, remember where the food was, remember how to fashion tools and communicate. In order to survive we had to move and move a lot. All of this movement requires a complex neural network to coordinate and control the movement decisions. When we exercise and engage in complex motor movements we are also exercising the areas of the brain involved in all cognitive functions.

This is where the ‘use it or lose it’ principle relates to brain volume. If we stop moving we no longer need such a large brain or all of those neural connections to coordinate and control movement. So, our brain begins to shrink. Unfortunately, this means that along with not being able to move as well as we used to we cannot think as well either. Everything is connected. If we want to keep our brains functioning at their peak, our bodies need to work hard.

My recommendation for brain health is daily exercise that is occasionally very vigorous. A combination of cardiovascular exercise and strength training will ensure the release of all of the important brain chemicals and hormones necessary to keep our brains active and healthy. Mentally sharp and physically fit – that is a great combination.