What Is VO₂ Max? Why It’s One of the Best Longevity Metrics You’ve Never Measured

If you’ve spent any time in the fitness or longevity space on social media (a wonderful, amusing, and sometimes scary place), you’ve undoubtedly heard about VO₂ max. So—what the heck is VO₂ max? Does talking about it make you a nerd? And should we care? (We’ll get to that; yes, being a nerd is cool; yes, we should care.)

What Is VO₂ Max?

VO₂ max (maximal oxygen uptake) is the maximum volume of oxygen your body can use during intense exercise, typically expressed in milliliters of oxygen per kilogram of body weight per minute (ml/kg/min).

In plain English, it’s a measure of how aerobically fit you are. Elite endurance athletes—like professional marathoners, cyclists, and cross-country skiers—often have eye-wateringly high numbers (north of 70 ml/kg/min). While part of your VO₂ max is determined by genetics, people with high scores have almost always spent years training at both moderate and high intensities to develop it.

That’s one reason why it’s such a powerful metric: as Peter Attia says, it’s a great aggregator of the work a person has—or hasn’t—done.

How to Measure VO₂ Max

There’s really only one way to directly measure VO₂ max: by exercising very hard (usually running on a treadmill or cycling on a stationary bike) while your oxygen and carbon-dioxide exchange is measured with a breathing mask.

Why such an ordeal? Because the “max” in VO₂ max means just that—you have to push yourself to the point where your body is consuming the maximum amount of oxygen it can. This usually takes about 10–15 minutes of progressively harder effort. The mask collects data on how much oxygen you inhale and how much carbon dioxide you exhale, allowing technicians to calculate your actual VO₂ max.

You used to have to visit a university exercise-physiology lab for this, but thanks to the growing interest in longevity and performance testing, many fitness or medical centers now offer VO₂ max testing. A quick Google search (“VO₂ max test near me”) will usually turn up several options.

A Few Practical Tips

Be forewarned: these testing centers are running a business and will almost certainly try to sell you additional tests—some of which may be interesting, others not. Don’t feel pressured to buy their “Longevity Package” if all you want is your VO₂ max score.

You should also ask about their testing protocol. Because it’s a maximal effort, you’ll want a thorough warm-up—not just for safety, but to perform your best. If their protocol doesn’t include one, ask why—or consider finding another facility.

Estimating VO₂ Max Without a Lab

There are plenty of ways to estimate your VO₂ max that don’t involve strapping on a mask or shelling out your hard-earned cash. Many fitness watches (Garmin, Apple Watch, Coros, etc.) use heart-rate and pace data to estimate VO₂ max, and there are several field tests you can do yourself.

All of them, however, still require effort—you can’t get around the “max” part of VO₂ max. I’ll cover these estimation methods next week in Part 2: How to Improve Your VO₂ Max.

Why VO₂ Max Matters for Longevity and Everyday Life

So, we know what VO₂ max is and how to measure it—but why should we care?

We don’t necessarily care about the exact number; we care about what it represents. Every physical activity can be expressed as a percentage of your VO₂ max. As I sit here typing, my body is consuming oxygen—just not much, since I’m not doing much.

At rest, I’m probably using around 3.5 ml of oxygen per kilogram per minute, which equals 1 MET (Metabolic Equivalent). If I get up and walk, I might be using 2 METs; if I go for a run, maybe 13 or 14 METs.

If I keep increasing my pace, eventually—no matter how hard I’m breathing—I’ll reach the limit of how much oxygen my body can use. That ceiling could be set by my heart’s pumping capacity, my lungs’ ability to move air, or my mitochondria’s ability to utilize oxygen. Either way, my muscle cells will start producing lots of lactate (not “lactic acid,” by the way) and those accompanying hydrogen ions that make muscles burn. I’ll soon have to stop (and probably question my life choices while gasping for air).

Why VO₂ Max Declines With Age

Being able to run fast isn’t required for survival (zombie apocalypse scenarios excluded). But oxygen is required for everything—from grocery shopping to climbing stairs. Unfortunately, VO₂ max naturally declines with age, and as it does, ordinary activities start demanding a higher percentage of your remaining capacity.

That’s why something that once felt easy—carrying groceries, walking uphill—can begin to feel like a workout. Your body has less oxygen “reserve,” so you accumulate lactate faster and fatigue sooner.

It’s one thing to be gasping after a 5-minute mile; it’s quite another to feel that way walking two blocks with groceries.

The Bottom Line

Your VO₂ max score is one of the best predictors of both fitness and longevity. The higher your capacity to take in and use oxygen, the longer and more independently you can live.

Next week, in Part 2, we’ll get into the good stuff: what you can actually do to improve your VO₂ max. It’ll be fun.

The Mighty Big Book of Stuff I Don't Know

My grandfather used to say*: “What I don’t know could fill a mighty big book.” And that’s true no matter who you are. Sure, you might know someone who “knows everything,” but they don’t actually. And, in fact, it might just be that they know a few things about something that you don’t. But we shouldn’t mistake casual trivia (or even in-depth knowledge about certain subjects) for blanket expertise. As far as we know, the human brain has a basically limitless capacity for learning, which is very cool, but even if you studied everything imaginable all day, every day, for the rest of your life, you would still be left in the same boat as my grandfather: knowing far less than what you DON’T know.

What does this have to do with longevity, health, and fitness? I think it’s important, as we all navigate this space, to understand who and what to listen to. There are a lot of people on social media, some with impressive credentials, who don’t say “I don’t know” enough. It’s not necessarily that they actually SAY it, but it’s how they deliver information. Do they cite their sources and do they cite them accurately? Do they speak in absolutes? (“Just do/don’t do this ONE thing and all your problems will be fixed!”) Do they give nuanced answers?

Generally speaking, the people I decide to pay attention to and follow are not only offering where their information comes from (i.e. which study), but they are also willing to discuss how the study might be limited. Science is incredible, but you can find studies that can be used to suggest almost anything. However, not all studies are equal in their rigor and the headline you might read about a certain study may be a gross oversimplification of what conclusions the study did or did not reach. Science also takes time and true scientists are not swayed by any one study. Instead, they gradually form or change their thinking based on the scientific consensus and the preponderance of evidence that that requires.

Also, as I’ve alluded to before, there are no silver bullets or magic pills. The human body is fabulously complex and the product of about a billion years of evolution, all the way from the basic building blocks of life, to single-celled organisms, to the first vertebrates, to apes, to us (with a few other steps along the way). And, like any complex thing, we know a lot, but there is still far more about the human body that we don’t understand.

For instance, we know comparatively less about human females than we do human males because the vast majority of studies only included males or were majority male. I don’t think you have to be an OBGYN to understand that there are differences between females and males, especially when it comes to hormones, but so much of the research has not included (or has not included enough) females. Even in the realm of seemingly basic, everyday stuff, like sleep or the perception of pain, an incredible amount of research has been done in just the last twenty years or so, and, again, there is still a lot that we do not understand.

Lastly, as I just mentioned, the human body, much like the world, much like humanity, is dizzyingly complex so I think it’s safe to be wary of anyone who says anything with absolute certainty. Even when it comes to seemingly simple questions, nuance becomes hard to avoid for someone who is being critical, honest, and rigorous. “Should I drink water?” Yes, absolutely, we need water for any number of our bodily functions and, to put it more bluntly, we need water to keep us from becoming un-alive. But, too much water in certain situations can be dangerous, even deadly. Just like too little water.

So, if someone asks, “How much water should I drink daily?” the answer should be more nuanced or we need to ask for more information. “How much water should you drink?” Well, that depends. What’s the temperature, humidity, and elevation? What activities are you doing? That answer is going to vary A LOT depending on whether you are relaxing indoors on a cool rainy day versus doing a 20-mile hike at elevation in the summer in the desert. Blanket, simple answers are attractive, but they aren’t necessarily helpful and, at times, they might even be dangerous.

In the end, I recommend looking for people who are willing to address the nuance in the world, who can discuss how and where they get their information, and who avoid speaking in absolutes and giving simple answers to complex questions. To that end, I think it’s important to let you know which figures in the health, wellness, and longevity space I turn to. The following people are not only experts in their field, but they are critical thinkers and they understand that the world is complicated and there are no (or at least very few!) absolutes, just a lot of nuance and context.

As Dr. Peter Attia, whose book, Outlive, started me on this journey, is fond of saying (though it’s not his quote): “The farther you are from shore, the deeper the water.” Which is to say that the more you learn about the human body or, indeed, anything, the more complex and confounding things get.

Let me know who you like to listen to in the comments below! And now, who I turn to (an incomplete list):

• Peter Attia, MD

• Andy Galpin, PhD

• Rhonda Patrick, PhD

• Layne Norton, PhD

• Mary Claire Haver, MD

• Brady Holmer, Phd

• Gabrielle Lyon, MD

• Michael Easter

*My dad’s dad died before I turned one so I never heard him say this, but my dad would say it.

A bit about me…

Hello!

I was born in 1986, which means I'm however old that makes me whenever you're reading this. But, as I’ve come to learn, calendar age doesn’t quite tell the full story. Like many of you, I’ve been on a health journey—certainly over the past few years, but also, in many ways, my entire life. The exciting part? I feel younger now than I have in over a decade.

And no, it’s not because of a pill or some expensive, futuristic treatment (more about my views on that in a later post). It’s because I spent the time and energy to study my body, reflect on what truly supports health, and build a more holistic, sustainable approach to feeling good—now and for the long run.

Speaking of long runs, I was lucky to discover running early. In ninth grade, after missing the basketball team the year before, I joined the cross country team to get in shape and I never looked back. Running became a lifelong passion that forged many of my closest friendships and continues to bring me joy. But my relationship with running hasn’t always been smooth.

Like many runners, I fell into the trap of only running—ignoring strength, mobility, stability, and power. That approach eventually caught up with me. Early in the COVID pandemic (sorry to bring it up), I developed sciatica. I had stopped bartending, started selling alcohol, and gained 30–40 pounds (of not-muscle), which I attribute mostly to poor sleep, stress, and focusing too much on carbohydrates at the expense of protein . (Turns out, much to my continued dismay, that martinis don’t pair well with restorative sleep, especially close to bedtime.)

Fortunately, I had both time (being mostly trapped indoors) and a bit of anatomical knowledge (from the brief time when I thought I was going to apply to physical therapy school) to self-assess and rebuild. I discovered the root of my sciatica were my weak and inactive glutes, which strength training began to address. Lifting weights has never been my preferred form of training, but I started incorporating strength, mobility, and stability work into my routine most days and my sciatica gradually went away.

But something still didn’t feel right. I was exercising regularly and more intensely than I had in years, especially thanks to the Peloton we got during COVID (shout out to Power Zone rides!), but I wasn’t happy with my body composition. I was heavier than I wanted to be and assumed, like many, that it was just part of being in my 30s.

Wrong!

Despite my dedication, I was unknowingly compromising my metabolic health by over-prioritizing carbohydrates, under-consuming protein, and continuing to miss out on high-quality sleep (martinis, alas). Over time, I began to shift course. I made small, science-backed adjustments to dial in my nutrition, improve my sleep, manage stress, and train smarter (and harder).

Oh, and sleep, by the way, is not just nice, it’s critical. Deep sleep helps regulate blood sugar, manage stress hormones, support testosterone production, and consolidate long-term memory, among many other things. It’s where recovery actually happens. And while I had always prioritized sleep quantity (thank goodness), I didn’t realize that my sleep quality was suffering, largely as a result of too much alcohol too close to bedtime.

Now, I feel as good—or better—than I did a decade ago. Regular checkups and blood work also support that. I obviously still have areas I’m working on (who doesn’t?!), but I feel confident that I’m setting myself up for success for the long run, and I’d love to help you too!

If you’re ready to start making changes to your habits to feel and perform better, book a free consult or, if you’re ready to dive in, fill out my questionnaire and schedule your initial session with me!

Why the Long Run?

What’s the deal with longevity anyway?

Is your social media feed full of people extolling the benefits of “Zone 2,” bragging about their VO2Max, frightening you about the effects of seed oils, or dissecting Bryan Johnson’s regimen for immortality? Maybe you’ve come across Dr. Peter Attia talking about healthspan or the Centenarian Decathlon? Or Dr. Andy Galpin discussing the physiology of high performing athletes? Or Dr. Mary Claire Haver discussing Menopause Hormone Therapy and the “menoposse?” Or Dr. Layne Norton talking about Muscle Protein Synthesis or HUMAN RANDOMIZED CONTROL TRIALS (IYKYK)? (Note: I’m a big fan of all of these people, along with many others, and they are all great resources). So, are we all going to live forever? Is there a secret pill or supplement or biohack you can take advantage of to be young and beautiful forever?

At The Long Run, I want to help people feel better, live better (and, hopefully, longer), for, well, the long run. Sadly, immortality and eternal youth are still only possible in the realm of science fiction and fantasy and we will (likely) never get an “exercise” pill that mimics all of the salubrious effects of physical movement. But the good news is that we CAN feel better, live better, and even “age in reverse” or maintain high function for many, many years, all without spending a fortune.

So, what’s the secret, you’re probably wondering? How is it that I feel (and look) better now than I did almost ten years ago? Am I doing “zone 2?” Am I using a red light therapy mask? Am I doing daily cold plunges? Am I sleepmaxxing? Do I eat paleo/keto/vegan/carnivore? Am I intermittent fasting? Am I taking creatine/ashwagandha/fish oil? Am I doing kettlebell workouts? Or am I only doing calisthenics? Do I walk 10,000 steps everyday? Do I spend hundreds (or thousands) of dollars a month on my wellness routine?

The answer to most of these questions is “no.” But I do do a lot of aerobic conditioning; I do (finally) have a good skincare routine; I do prioritize sleep (and I avoid social jet lag whenever possible); I consume more protein than I ever have (mostly in the form of Organic and Grass Fed beef or Maui Nui jerky sticks); I do take a daily fish oil supplement for Omega-3s; I don’t have kettlebells, but I love my adjustable dumbbells; and I try to walk as much as I’m able (sometimes with a weighted backpack).

Obviously, there is a lot to unpack here, and we could spend a lot of time talking about any one of the above trends or techniques, and we will. But I also believe that most people can improve how they feel, look, and interact with the world by making changes and getting more out of their sleep, their nutrition, and their movement. The good and bad news is that there aren’t any quick fixes, but there are fixes that can be implemented quickly! And that is doubly good news because I want – and I hope you want – to make durable changes. If one good action could get us a six pack or improve our VO2max by 20 ml/kg/min overnight then it stands to reason that one bad action could just as easily reverse those gains (or worse).

So, where do we start? If you’re interested in learning more, I encourage you to fill out my onboarding questionnaire and schedule what I hope to be the first of many virtual sessions together! The first step is making sure that, for where you are in your life right now (because our lives are always changing, and we need to acknowledge that), your sleep, nutrition, and movement are all helping you move in the same direction and I will help you make a plan to do that. Once we have done that, we can work on more specific goals, or how to get as much out of your current season of life in order to set you up for success for your next season!

Finally, none of what I’m offering is in any way medical advice and you should absolutely get your annual physical. Modern medicine is a wonder and we should all be making use of it. However, I encourage you to advocate for yourself, especially if something does not feel right. And if that means shopping around for another doctor or specialist that hears you and makes you feel more comfortable, please do so. Alright, if you made it this far, thank you and I look forward to helping you make progress over the long run!