Getting a Baseline (VO2 Max)
- Mike McMullen
- Jul 5
- 8 min read
And now for something completely different...
Having concrete examples of applied theory helps me learn, and with medicine that means real life patient examples. In that spirit I am going to use this blog post to go through how I interpret and make plans based on test results. What better way to do this in a HIPPA compliant manner than to share my own data.
So to kick this off I am going to go through my recent VO2 Max results from June of 2025.
Look at those beautiful graphics. You can find the full PDF of the report attached at the bottom of this blog should you want to read the two page report in its entirety.
First off, what is a VO2 Max? It is a super hot test in longevity medicine these days. The test is typically done on a treadmill or bike, you are hooked up to a face mask and wearing a heart rate sensor, and you exert yourself until failure (you run/bike until you can't run/bike anymore). The test is grueling by definition, but I think it is the best test out there. I would also argue it is one of the few tests that anyone physically capable of getting should definitely get.
For deep dives into VO2 Max, I would start by going down the rabbit hole with Peter Attia. For now I am going to focus us on how I look at my own test.
You can get a lot of data from a VO2 max test but the most important piece of data is the actual VO2 max (hence the name of the test) reported in mL/Kg/min. This is, as the units indicate, the amount of oxygen in mL that your body can consume per Kg of body weight per minute at your maximal effort. Basically, it tells you how efficient your body is at getting and using oxygen. You can see mine on this most recent test is 50.6 mL /Kg/Min.
Sweet Mike, you are excellent for your age... but what do I do with that number?
Great question. This number tells me a lot about my overall health. In order to get a high number here, I need to generate enough output from my muscles to use up a lot of oxygen. This means I need a 1)decent amount of muscle mass, those muscles should be 2)powerful and 3)efficient, and they need to be using the oxygen given by being 4)well stocked with resources, 5)be able to efficiently extract additional resources from the blood, and 6)have super healthy mitochondria to generate power from those resources. Now that we have the demand part established, I need to meet this demand with ample oxygen and glucose which means I need to 7)have lungs that can pull in ample amounts of oxygen and 8)have super healthy tissue to facilitate the gas exchange from the air into my blood. I then need 9)a strong heart and 10)prime vasculature to bring that oxygen rich blood to the muscles and 11)bring the used blood full of metabolic detritus like carbon dioxide and lactate back to the lungs to be exhaled out. I also need 12)an optimized liver and 13) stud of a pancreas to regulate the blood sugar and other metabolic factors. Remember, this tests by design stresses this whole system until it fails so: if a link in this chain fails early, I get a shitty low VO2 max number; if all the links in the chain stay strong I get an awesome high VO2 max number.
So, to reiterate:
To get a high VO2 max number you need excellent muscles, an excellent cardiovascular/respiratory system, and the will to use them!
Don't underestimate this last part. As this test is limited by what you perceive to be your maximum exertion, people who tap out of the test early and do not stress their system to the max, will not generating an accurate number reflective of their true maximum oxygen consumption. I would love to go into a whole 'side spiel' on what discomfort tolerance (or lack there of) might indicate for longterm health outcomes, but for now I will chalk it up to being outside of the scope of this discussion.
Of note, there were a few big studies, a popular one being a paper by Kokkinos et al 2022 (PDF of the study is attached below) that showed an enormous difference in the risk of death given someone's VO2 max.
Using just this single number, you can get a better predictor of your risk of death than by looking at smoking history, kidney disease, heart disease, diabetes, or cancer. Absolutely incredible! And for those not used to looking at graphs and hazard ratios in this literature, these differences in relative mortality risk by VO2 max are staggering!
And here is the thing, what is really nice about knowing your VO2 max is not just that it is extremely predictive of quality of life, functional capacity, and risk of death, but that it is also extremely modifiable. Unlike other metrics, you can train and make incredible changes to your VO2 max. You can also track it over time to see if the interventions you are doing are working. Thus, it is a test that puts the power of longevity into your own hands.
So, now to the question posited earlier in this blog post: what do I do with this number, my number, my 50.6 mL /Kg/Min.
First of all, I pat myself on the back. Nice job Mike, you have 3 kids, 2 dogs, and are going back to medical residency and you haven't completely fucked up your health. 2 gold stars! Really, a 50.6 is a good number for my age. It is telling me that I am doing enough to keep my health and reinforces that my current routine of exercise, nutrition, and sleep are effective. Also, it allows me to compare to where I was before.
Below are a VO2 max test I had done when I was 35 and another one when I was 36 years old:
Now we have context. I can see that going from 35y/o to 36y/o I actually increased my VO2 max, which reflects my increased focus on exercise during that intervening year. The slight drop from 36y/o to 37y/o again reflects that I deviated a bit from my exercise routine. Now string together one to two decades of yearly VO2 maxes, and you will start getting a really good picture of my overall health and trajectory.
It is worth noting that your VO2 max predictably falls with age assuming you don't meaningfully change what you are doing. The rate of decline varies a lot by person, but a good rule of thumb is about 1% per year or 10% per decade. It then falls off a cliff when you turn 75.
So as I am looking at my current VO2 max, I am always projecting into the future. If I am X mL/Kg/min at 37y/o, I will be Y mL/Kg/min at 47y/o, and Z mL/Kg/min 57y/o, and A mL/Kg/min at 97y/o...
Specific to me, my goals are not to podium a triathlon in my 40s. Instead one of my actual centenarian decathlon goals is to podium a sprint triathlon in my mid 80s. This means I need to keep my VO2 max up over the next several decades, meaning that training for that race 5 decades in the future starts now. I have to focus on avoiding injury as well as building reserve and delaying decline. That is what I am pulling from my VO2 max number of 50.6 mL /Kg/Min.
I am seeing that a 2 mL /Kg/Min decline from last year is a bigger drop than I would like if I am going to get my VO2 max in the elite range when I am in my mid 80s. To this end, I have decided to bike to work every day in residency as a built in training regiment. I am also intentionally directing my bike route home after work to involve going up a large steep hill. This in effect builds in daily VO2 max training inclusive of both with the zone 2 training on the flats and VO2 max training on the hill. Because time is limited, I have used my commuting time as training time. The good ol'e 'twofer'.
Additionally, and I am not advising that anyone try this, I started taking 5mg of Tadalafil (brand name Cialis) every morning. This is a phosphodiesterase 5 inhibitor and will do two things for me. 1) I expect it to increase the blood flow to my muscles as I train on my bike and with lifting as the Tadalafil increases vasodilation and blood flow. And 2) given my family history and genetic risk factors for being at increased risk for BPH and prostate cancer I think both conditions will be better controlled in my future self if my current prostate receives extra blood flow in my 30s. Of note, there are other benefits to this particular regiment that are outside of the scope of this blog.
Again, insert all the legalize clauses. I am not your doctor, no doctor/patient relationship was established, go ask your doctor, I am not saying you do this... etc. Just letting you know what I am tyring.
In addition to biking and Tadalifil daily, I am making focused efforts on maintaining my muscle mass by lifting every morning before work. We will cover DEXA in another post, but this muscle maintenance is incredibly important for the VO2 max test as explained above.
I will follow up these 3 interventions by repeat my VO2 max yearly to see if they are working, with the potential of doing it every 6 months if I have a specific question I am trying to answer.
Now, there are a lot of other things you can pull out of a VO2 max test other than the single number of your VO2 max. Metrics such as max heart rate, training zones, rate of heart rate recover post test, etc, can all be pulled from a VO2 max test. All of these metrics can be interpreted and inform aspects of your health. However, I am not including them in this post because I feel they are much much much less important than your VO2 max number. So, I urge you, if you go down the rabbit hole of learning all the nuances of the VO2 max test, don't loose the forest for the trees. Keep you eye on the goal and focus on that big beautiful number of VO2 max!
To bring this to a close, let's cover some logistics. I got my VO2 max at the GW Metabolism and Exercise Testing Service located in a Milken Institute School of Public Health Building. The facility was clean, up to date, and the overall experience was excellent. Andrew, who walked me through all the testing and results was incredible. Cannot recommend this place enough. And no, I do not have any financial interests to disclose.
If you want to get your own VO2 max, there are a ton of places, be them academic centers like GW, gyms, and imaging centers. You can google or ChatGPT what is in your area and call ahead for pricing, protocols, and what test results you can expect. Anticipate pay somewhere between $100-$200 out of pocket, and no, insurance will not cover this as of the writing of this post.
If you have any hesitation on whether or not you are health enough to do this test (i.e. you are afraid you are going to drop dead from exerting yourself), you can take the Par-Q questionnaire. Most centers will do a little screening to make sure you are eligible from a safety standpoint for the VO2 max and will likely use the Par-Q or something similar.
I highly encourage you to get this metric. Again, it is the single lab test that most accurately predicts both your longevity and quality of life, it is modifiable thorough deliberate action, and tracking it over time by getting your baseline VO2 max now will help you stay focused on the long term goals amid the chaos and shitshow that is life.
Stay positive, stay kind, and keep fighting the good fight.
-Mike
PDF of VO2 max at 37
PDF of Mike's VO2 max at 36
PDF of Mike's VO2 max at 35
VO2 max Study
Par-Q questionnaire
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