Blog #9 Measuring Health through VO2 Max

Writing this piece as the train rattles back home, I find myself reflecting on the spectacle of the 2024 Paris Marathon—an event that I had long desired to participate in but, due to a recent skiing accident, was subjected to witnessing from the sidelines. Despite my personal setback, the opportunity to observe elite athletes pushing their limits was a profound experience, serving as a vivid reminder of the meticulous planning and dedication required for such endeavors.

Marathon training, as many enthusiasts know, demands extensive preparation, spanning weeks or even months. It entails a systematic progression, gradually increasing distance and intensity to fortify endurance. The result of this dedication is training loads that have a significant impact on physiology, particularly over time (weeks, if not months or years of consistent work). These occur both at the microscopic level of the mitochondria where energy production becomes more efficient, to the macroscopic level where blood vessel growth and formation leads to larger delivery of nutrients to the tissues (ie. angiogenesis). As I marveled at the competitors hurtling towards the finish line, their strained expressions betraying the exertion, I couldn't help but draw parallels between their athletic pursuit and the broader pursuit of health and longevity.

But in the pursuit of bettering our health, what is our litmus test, or our measurement, for progress? Life is a marathon, and we should be training for it with similar foresight and commitment, particularly if we want to improve the quality of our years later down the line. But unlike runners and other athletes, how the heck do we gauge our improvement in health? How do we ensure what we are doing actually makes us healthier? 

For the elite runner, or any really any athlete, he or she can pay attention to their perceived exertion (ie how “easy” it feels) at a particular pace and intuitively appreciate their change in fitness week by week. While maybe not perfect, it is a fairly straightforward and largely foolproof process.

However, when it comes to judging health we humans are notoriously poor. In my experience as a physician, patients often cite subjective feelings of wellness or old athletic achievements as indicators of their current state of health. Furthermore, standard metrics at the doctor’s office (e.g. blood pressure, heart rate, oxygen saturation, body mass index) only provide a partial view into a person’s overall health. While measuring blood pressure is important for evaluating the development of cardiovascular disease, it does little in the way of telling us if we are, so to speak, “getting healthier” with the changes we are trying to make. I should be clear - blood pressure does improve with better practices in nutrition and exercise. But once it has corrected (if we are assuming is was abnormal in the first place), how do you monitor your own progress further? 

I bring this up because what medical providers do in the clinical setting often fails to provide patient’s with a comprehensive view, or feedback of their health. So enter VO2 max, a health metric you might have heard about but should definitely be more familiar with. 

Without getting lost in the details, VO2 max is simply a measure of the body’s efficiency to use or consume oxygen (specifically, the amount of oxygen normalized to body weight, used per minute at max intensity, measured in ml/kg/min). The more oxygen a person can utilize at a given level of exertion or intensity, then the more energy he or she can produce. This metric is so commonly discussed within endurance athlete circles because it directly informs how well someone can perform in regards to aerobic exercise.

So if you aren’t an endurance athlete or the typical marathoner charging through some city’s streets on race-day, why should this still matter to you? 

Because it is one of the few, and now very accessible, tools we have that not only directly measures fitness but also predicts life expectancy. Within the scientific community, there is a lot of discussion as to whether this metric is “too good to be true.” While we only have a limited number of high quality studies by means of randomized control trials and meta-analyses (largely due to the logistical challenges of studying long-term interventions) there are mountains of observational studies and other clinical studies linking higher levels of aerobic fitness to reduced burden of chronic disease and all-cause mortality. 

Given the aforementioned, one would naturally assume this might be a more emphasized and integrated piece of discussion at the routine health visit for a patient. But classically it hasn’t been because of the lack of access to high end sports medicine labs and limited correlational data across multiple testing modalities (e.g. how do alternative testing methods such as grip strength directly compare to the standard sports lab treadmill test for VO2 max). While the primary care setting is still lagging behind, my hope is that this metric becomes much more mainstream with time. Now that testing, and even estimations, of VO2 max is more readily accessible there shouldn’t be an excuse to avoid translating this metric into the clinical space for patients. 

In my view, integrating VO2 max assessment into routine medical care represents yet another needed shift in healthcare—one that empowers individuals to proactively manage their health. By understanding their baseline VO2 max and monitoring changes over time, individuals can tailor their lifestyle choices to optimize health outcomes across lifespan.

Furthermore, discussions around VO2 max with healthcare providers can serve as catalysts for informed goal-setting and personalized health planning. Whether aiming to improve fitness, mitigate disease risk, or enhance overall well-being, leveraging VO2 max as a guidepost holds immense promise in steering individuals towards healthier, more resilient futures.

This article merely scratches the surface of the topic, offering a glimpse into VO2 max as a transformative health metric. In future installments, I'll delve deeper into its significance, applications, practical implications, and my own personal recommendations. Until then, I encourage you to explore resources on VO2 max and stay tuned for upcoming discussions on this vital aspect of longevity medicine.

Cheers!