Why We Age

We’re all getting older.  So, what else isn’t new?  Recently I was reviewing Peter Reaburn’s The Masters Athlete.  The first chapter sets the stage for the rest of the book by describing the aging mechanism.  Ultimately, it comes down to what is happening in our cells, the building blocks of our bodies.  I thought it might be of interest to readers to review the major theories of cellular aging and function.  The caveat is we are each somewhat unique individuals and as we age our differences are increasingly revealed.  Also, the factors discussed are interactive and some may be more dominant in one part of our lives than others.  Full disclosure, I have drawn liberally from Peter’s book in writing this post.

So, here are six theories of aging impacting the senior runner listed in The Masters Athlete:

• Cellular Degeneration.  Cells respond variably to free-radical oxidation, which is essentially an unstable oxygen molecule reacting with other molecules. This process essentially destroys the cell. Not necessarily to be avoided, free-radicals present themselves when we do intense workouts. The guardian response is healthy cells produce oxidases, which essentially neutralize the free-radicals. However, as we age oxidase production declines, thus free-radicals have greater opportunity to do their damage.  When a cell dies, its DNA, the blueprint for new cells, is destroyed.  Since cells normally die at a rapid rate, cell regeneration is essential.  If this process is damped, we go downhill!
• Genetics. Reaburn suggests this is probably the major determinant.  Somewhat jokingly he suggests we pick our parents well!  In any event, our genes influence the other five factors discussed in terms of timing and degree.  Also, the expression of genes is affected by environmental factors, such as whether we smoke or live high-stress lives. Bottom line, genes guide our immune response, the function that helps keeps us healthy.
• Hormonal Control.  With age, secretion of growth hormone and testosterone decreases.  These hormones fuel regeneration of muscle, tendons, cartilage and connective tissue, collectively the essential network for movement.
• Wear and Tear. This is something of a use-it-and-lose it corollary.  Cars driven hard, even when regularly serviced, begin to fail.  Our bodies are like that too!  Added to this, aging is often accompanied by a decrease in the rate of protein formation, a vital function in keeping our chassis up to snuff.
• Waste-Product Accumulation.  This one is a little gross.  Imagine if we had incomplete elimination over a period of time.  Things would build up and maybe back-up. At the cellular level a substance called lipofuscin can infiltrate various types of cells.  Lipofuscin is yellow-brown lipid byproduct of free-radical oxidation that accumulates in heart, kidney, liver, and nerve cells.  By the time we’re 90 some cells can be 7% filled with this stuff, affecting their function and vitality.
• Cross-Linkage. Some linkage among cells is critical. The interconnections in our body are pervasive. However, with aging some linkages form larger molecules that resist repair processes.  The result is tighter ligaments, tendons, and muscle coverings, reducing our flexibility and thus performance.    

This is a lot to take in and it might be depressing at first.  In our 40s and even 50s, we didn’t think about this stuff.  But things are what they are. The good news is we do have a fair bit of control, or at least influence, over the pace of some of these impacts.  Diet, exercise, sleep/rest, and proper recovery give us the best chance to delay or ward them off.  Let’s do what we can!