Cardiorespiratory fitness knows no age.

Allow me a proud alumni moment. There is some awesome new and highly generalizable research coming out of A.T. Still University, where I had the opportunity to study under and collaborate with some of the most brilliant health and exercise scientists I have ever met. Not just as a scientist, but as a former athlete who is beginning to come to grips with the working capacity and cardiorespiratory fitness diminishing realities of aging, I am realizing that there may be a silver lining to all that hard work I put in when I was competing.

Possibly my favorite professor ever, Dr. Jack Daniels, examined data from former world-class runners over half a decade in hopes of gaining some perspective on the “staying power” of fitness over a lifetime. As a running coach, Daniels first gathered standard metrics of cardiorespiratory fitness, including maximum heart rate, VO2 max (oxygen consumption during maximal effort exercise), and VEmax (amount of air moved in and out of lungs at maximum effort) from a group of 26 elite competitive runners in 1968. 25 years later, in 1993, interested in how time and diminished focus on competitive running had altered their cardiorespiratory fitness, Daniels was able to gather all of the original participants for some questioning regarding their current exercise habits and perform another round of testing. Then in 2012, one of Daniels’s research assistants suggested that he attempt to gather the same group of former runners, now in their late 60’s and early 70’s, for a final round of questioning and testing. Although most of the participants had remained physically active throughout the entire nearly half a century timespan, by 1993, none of them were still competitively running, and by 2012, most of the remaining 22 study participants did little exercise outside of occasionally walking. However, their cardiorespiratory fitness remained at a far higher rate than expected. They all placed well within the 90th percentile for VO2max, VEmax, and several other metrics of cardiovascular health (i.e., resting heart rate and blood pressure) for their age group, several still within very healthy ranges for active individuals less than half their age, even after not having done any intense training in decades.

This must come down to genetics, right? These participants were physiological outliers, several of them so elite from a fitness standpoint that they had competed in the 1968 Olympics. But that doesn’t explain the whole picture. Not only had the study participants started the inevitable cardiorespiratory fitness decline from heights that the rest of us can only dream of, but in terms of percentage of capacity lost per decade, that fitness remained at an anomalous level despite reverting to normal activity levels following the culmination of their competitive careers. The enduring nature of cardiorespiratory fitness is a topic that we still know little about. Research has shown significant declines in metrics of endurance performance and cardiorespiratory health with as little as 4 weeks away from regular training. We begin to show physiological signs—as determined by levels of the enzymes citrate synthase and succinate dehydrogenase in the blood—of diminished capacity in half that time. But that doesn’t paint a clear picture of time course loss of cardiorespiratory health. Anecdotally, I have found that nearly a decade (and a few dozen pounds) removed from competitive running, I still have enough in the tank to surprise some people when challenged (by some people, I mean my wife). And believe me, I am no genetic outlier when it comes to cardiorespiratory fitness: the stain on my academic pedigree is a “C” in my 7th grade Physical Education class because 11-year-old Dr. Rodriguez was unable to run a sub-10 minute mile.

What the data suggests is that the human body may be able to hold onto fitness like a squirrel packing their mouth full of nuts in preparation for hibernation. Intense exercise causes semi-permanent positive physiological adaptations that we still can’t totally explain, possibly attenuating fitness losses that are an unavoidable part of aging. How? The mechanisms aren’t totally understood, but I know several exercise scientists who may want to contact their institutional review board about some new research proposals. I’m up for co-authorship. And for those of you in your athletic peak, don’t miss an opportunity to run, and run fast, before your aging joints make it increasingly difficult. You can thank me in 50 years.

Dr. Damian Rodriguez is the health and exercise scientist for doTERRA International, LLC. He holds a doctorate in health science, a master’s degree in exercise physiology, and countless professional certifications. He has spent most of his life researching nutrition, exercise, and the lifestyle behaviors associated with optimal health. Along with his passion for health, as someone who lives with Asperger’s Syndrome, he is also involved in bringing awareness to autism spectrum disorders. There are varying opinions about many health and fitness topics. His opinions are his own and not necessarily that of doTERRA International, LLC. Consult your healthcare provider before making any changes to diet and exercise.