By Susanne Michaud, DPT, OCS

I am a constant runner.  I run because it is the fiber of my being, the ya ya’s in my cells, the therapy for my blahs, the generator of my ideas, my connector to everyday nature. I’ve run consistently for 36 years, give or take time out for injury, since joining the track team in 1982.  So I am indeed an aging runner and it is my goal to run until the end of my days.  Choosing my careers in massage therapy, yoga and physical therapy sprung from my selfish desire to sustain my running.  In this article, I share some insights I’ve gleaned over time to keep people running over their lifespans.

Aging is not a disease.  Normal aging however, does involve the drying out of all of the tissues of the body.  Connective tissue (which includes bone, tendons, ligaments, cartilage, fascia and blood) is perhaps the most affected by this desiccation process.  Aerobic exercise demands greater hydration.  So the aging runner must doubly attend to their intake of water and electrolytes.  Disease, injury, and inactivity can accelerate the aging process.  But, on the up side, it’s now well known that exercise is truly the fountain of youth in curbing the deleterious effects of disease and aging.

Once upon some time ago, I was a somewhat fast runner…  In my 30’s, my marathon PR was 3:46 and half marathon was 1:42.  In my 30’s, running an 8-minute mile pace was easy peezy.  Now in my 50’s, that speed eludes me.  I’m happy if my 10K pace is a 9 minute/mile, but in reality it’s more like 9:30 (I blame it on the hills of Seattle).  But how does aging slow runners down?

The answer may be in our ability to consume and use oxygen. The measurement of the maximum amount of oxygen that our body can use during intense exercise is called VO2 max.  Research shows that the aging runner’s VO2 max is diminished.  The main reasons for this diminishment are likely related to (1) changes in the heart and vessels, (2) changes in skeletal muscle mass and enervation, (3) body composition changes, and (4) training changes.

A reduction in our heart’s capacity to pump blood efficiently due to age related changes affects blood flow to working legs.  Stiffening of the heart and arteries due to atherosclerosis (and dehydration) reduces the hearts ability to pump blood, like a rubber bands’ loss of elasticity over time. But fear not.  With only 30 minutes of exercise 5 days a week, one can increase the elasticity of the heart by 25%. So heart healthy diet and habits, good hydration, and regular exercise, such as running, may help to improve the pumping of blood to runners’ legs.

Age related VO2 max reduction is also linked to the loss of skeletal muscle (sarcopenia) or the reduced ability of the skeletal muscles to contract.  If not maintained with regular weightlifting, muscle mass is lost at 15% per decade from age 50 to 70 and 30% per decade after age 70!!![1]  The good news is that multiple research studies show that loss of muscle mass is not inevitable and is reversible (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2804956/).  Therefore, the antidote to this age related decline in muscle is to actively engage in both resistance and aerobic exercise, to not only keep us running but to improve our running performance.

Body composition, which is the amount of lean muscle mass versus body fat content, may also contribute to our slowing pace.  The good news is that those who regularly stay active usually remain within 3 lbs of their younger active weight, versus those who stop running, who usually gain up to 20 lbs of mostly fat as they age.  As a menopausal woman and self proclaimed foodie, this is a challenge for me and one I will need to remain conscious around, since the pay off is that running is easier when I’m lighter.  Benefits of staying light on ones feet as we age include lower cholesterol, reduced risk of heart disease, and reduced wear and tear on joints.

Training regimens as we age also affects our ability to efficiently use oxygen.  A reduction in training volume and intensity accounts for this decrease in VO2max .  Often this change in volume and intensity results from longer recovery times needed – older runners are not the super healers they once were in their youth.  Tim Noakes, MD, writes in his book, The Lore of Running, “A general rule is that older runners perform better on less training since the margin between optimum training and over training is much less which makes it easier to overstress the older body and to perform poorly as a result.”  In other words, most training programs are designed for the runner at their peak, so the older run (those over 45) should adjust these programs to 60-75% of the recommended amounts.

Beyond VO2 max, other explanations for the slowing of the aging runner may include changes in the body’s capacity to absorb landing forces, and chronic orthopedic disabilities.

A common dismissal of running is that all the “pounding” is damaging, therefore it is not good for you.  This is not necessarily true.  A Stanford University study in 2008 studied over 500 older marathon runners over 20 years and compared them with their non-running age-matched counterparts and found that the people who did not run had a greater incidence of knee arthritis than the runners, with the exception that the runners who had prior destabilizing injuries to the knees (e.g., torn ACLs and removed of menisci) faired the same as the non-runners with their incidence of arthritis.  So “pounding the pavement” actually preserves the cartilage in the joints, unless the cartilage has already been injured.

The shock absorbing mechanisms in our tendons and tissues does diminish as with age.  A function of our connective tissue, particularly our tendons, is to act as a spring (think pogo stick), storing and releasing energy when the foot contacts the ground.  The “drying up” of our connective tissues as we age serves to stiffen our tendons and joints and is likely the biggest reason we lose the spring in our steps.  When the spring has sprung, then the body’s ability to attenuate the “pounding” forces while running are impaired.  Learning efficient running mechanics helps to reduce this failure of the tissues to bounce back.  Also, giving the tissues mini-breaks with walking interspersed in a run also improves endurance as well as recovery time – a practice that all ultra-marathoners cultivate to withstand the demands of distance.  So we run smarter not harder as we age, right? RIGHT!

The bottom line is that running into our golden years is good for you if you heed the signs and respond accordingly.  The take home message for those of us who want to start or continue running is that we need to stay strong, stay hydrated, run efficiently, train smart, stay lean, rest and recover well, and accept that we may be a little slower than our younger selves.

[1] Noakes, T., Lore of Running, 4th edition, Human Kinetics, p. 82