VO2 Max Myths

VO2 max has become the hottest metric in fitness. Every podcast, every longevity guru, every Apple Watch notification is screaming at you about it. And look, the underlying science is real and important. But a lot of what you're hearing is either oversimplified, misquoted, or flat out wrong.

VO2 Max Defined: The maximum rate at which your body can take in, transport, and utilize oxygen during intense exercise, measured in milliliters of oxygen per kilogram of body weight per minute (ml/kg/min). It reflects the combined capacity of your lungs, heart, blood, and muscles to deliver and consume oxygen at peak effort. Basically: It measures how much oxygen you can pull in and put to use when you're going all out.

After 25+ years of training clients in NYC and watching fitness trends come and go, I've learned to be skeptical when one metric suddenly becomes the answer to everything. VO2 max is the latest victim of this treatment. So let's clear some things up.

Here are the five biggest VO2 max myths I run into all the time, and what you should actually pay attention to instead.

Myth 1: VO2 Max Is the Single Greatest Predictor of How Long You'll Live

This is the big one. Peter Attia popularized this claim in his book Outlive and across hundreds of podcast episodes. He's called VO2 max "the single most powerful marker for longevity" and provided specific percentile targets by age and sex.

Here's my issue: most of the longevity studies being cited NEVER actually measured VO2 max.

The commonly referenced 2018 JAMA Network Open study by Mandsager et al. mapped treadmill performance onto VO2 max percentiles rather than directly measuring it. What those studies actually measured was exercise tolerance through metabolic equivalents (METs) at peak effort on a treadmill. That's a different thing. Eric Topol has pointed out this same discrepancy, and the folks at Barbell Medicine have done a great job hammering home the same point on their podcast. Breaking down all of cardiorespiratory fitness down to one lab metric is shortsighted.

Now, before you throw your fitness tracker out the window, let me be clear about something important. Tracking your VO2 max isn't a bad idea. If your VO2 max is going up over time, your cardiovascular fitness is almost certainly improving, and that absolutely does correlate with better longevity outcomes. The metric itself isn't the problem. The problem is treating one number as the holy grail when it's really just one piece of a much bigger puzzle.

Think of it like tracking your weight on a scale. The scale gives you useful information, especially over time. But if you only ever look at the scale and ignore body composition, strength, energy levels, blood pressure, and how your clothes fit, you're going to make some pretty bad decisions about your health. Same deal with VO2 max. Use it as one data point in a broader picture, not as the only thing that matters.

Does cardiorespiratory fitness predict longevity? Absolutely. Nobody is arguing against that, including me. But obsessing over a specific VO2 max number when the research is really about broader fitness is missing the forest for the trees. It's like saying your bench press max is the single greatest predictor of upper body strength. Is it correlated? Sure. Is it the whole story? Not even close.

A note on Attia: In early 2026, emails between Attia and Jeffrey Epstein were released as part of the DOJ's Epstein files. He resigned from CBS News and stepped down from other roles. He has not been accused of any criminal wrongdoing and stated he was never on Epstein's plane, island, or at any parties. His science communication on VO2 max and longevity is still useful, even if the specific percentile targets deserve more scrutiny than they've gotten. Separate the science from the scientist.

Myth 2: You Need a Lab Test to Know Where You Stand

The fitness industry loves making simple things feel expensive and exclusive. But you don't need a metabolic cart and a $200 lab visit to gauge your cardiorespiratory fitness. I've been training clients for almost three decades and I've never once needed a lab-measured VO2 max number to design an effective program.

VO2 max is one of many components that make up aerobic fitness. It's a poor predictor of who's actually faster or fitter among trained individuals. Alex Hutchinson (one of my fav exercise science writers) has documented college walk-ons who outscored Olympic medalists on VO2 max but ran 10% slower because their running economy, lactate threshold, and other factors weren't there.

Think about it like this: VO2 max is the engine size. Important? Yes. But if you want to know whether that car is going to win the race, you also need to know about the fuel tank, the tires, the aerodynamics, and whether the driver is any good. Engine size alone won't cut it.

For the average person trying to live longer and feel better? Go run a hard mile (or bike or row). Track your performance on over time. If your times are improving, your fitness is improving. Which means your longevity prospects are improving. You don't need a number from a mask strapped to your face to confirm what your body is already telling you.

Myth 3: You Have to Do Specific "VO2 Max Intervals" to Improve It

When people hear "train your VO2 max," they immediately think of brutal 4x4 minute protocols done at maximum effort. The Norwegian 4x4 protocol (four minutes hard, four minutes recovery, repeated four to six times) works, sure. It is hard as hell and most regular folks are not doing it consistently. But, thankfully, it's not the only thing that works!

Both high intensity interval training and moderate intensity continuous training can improve VO2 max similarly, depending on how it's done and how much of it you do. Intervals longer than two minutes seem more effective than shorter ones, but the key variable is consistency, not complexity. I've been telling clients this for years and the research keeps backing it up.

For every incremental improvement in cardiorespiratory fitness, you reduce your risk of premature death from any cause. That means your Zone 2 rides, your long runs, your 30 minutes on the rower all count.

The best protocol is the one you'll actually do three or four times a week for the next decade. Not the one you saw on a podcast, did twice, and then abandoned because it made you want to crawl into a ditch.

Myth 4: Your VO2 Max Is Mostly Genetic and There's a Hard Ceiling

This one is half true and half defeatist. Yes, genetics play a role. Some people are born with bigger engines. The Norwegian cyclist Oskar Svendsen tested at 96.7 ml/kg/min at his peak and still clocked 77.0 after 15 months of zero training. Life isn't fair. We established this when you saw your first person with abs who "doesn't really work out." Some folks are born with the winning genetic lottery ticket. I always wonder how many people out there don't know they have a winning ticket.

But the data on trainability is wildly encouraging, and this is the part most people miss: going from low fitness (bottom 25th percentile) to just below average is associated with a 50% reduction in all-cause mortality. Getting to above average drops that risk by 60 to 70%. You don't need to be elite. You just need to not be sedentary. It is as easy as getting off the sofa and moving a bit more.

This is the most important takeaway from the entire VO2 max conversation and the one most podcasters blow right past. The biggest bang for your buck isn't going from good to great. It's going from the couch to anything.

There's also a wrinkle most people don't know about: the traditional idea that VO2 max represents a hard physical ceiling set by your heart and lungs may not be the full picture. The central governor theory suggests your brain may be imposing limits before your cardiovascular system truly maxes out. The ceiling might be more elastic than we thought. Translation: you've probably got more in the tank than you think.

NOTE: There is no good data that higher Vo2 Max levels continue to correlate with improved fitness performance and health. Beyond the "above average" level, there is no reduction in risk factors. It serves to differentiate between good and poor levels. For instance, a VO2max of 75 is faster than 45. However, once individuals reach a decent level, it doesn't differentiate performance. Therefore, a Vo2max between approximately 65 and 90 has little significance.

Myth 5: If You Lift Weights, Your Cardio Doesn't Matter (or Vice Versa)

This one still floats around in strength training circles and it needs to die. I've been saying this for years. You need both. Period.

The folks at Barbell Medicine have a "Vital 5" framework for longevity that includes:

1. Blood pressure

2. ApoB

3. VO2 max

4. Relative strength

5. Body composition

Not one or the other. All five. And in my experience, lifters who skip cardio always end up gassed during their last few sets, and runners who skip lifting end up with the kind of injuries I have to spend months helping them rehab.

NOTE: Data suggests strong social engagement is the greatest predictor of longevity. Not as sexy as Vo2, METs, or grip strength. So do some cardio with your friends...double whammy!

For my lifting clients, I usually recommend cycling and rowing for conditioning work because they're low skill, low injury risk, and don't generate the kind of residual fatigue that wrecks your squat the next day. For my cardio-only clients, even two days a week of resistance training can transform their performance and dramatically reduce injury risk.

And here's the thing nobody wants to admit: you can be fit and fat. You can also be skinny and wildly unfit...this is affectionately called 'skinny fat'. The number on the scale tells you almost nothing about your cardiorespiratory fitness or your strength. Stop using it as a proxy for health. Resistance training combined with regular cardio is the move.

The Bottom Line

VO2 max matters. Cardiorespiratory fitness matters even more. But the internet has turned a useful metric into a status symbol and an anxiety trigger. You don't need a lab, you don't need a $100K concierge doctor, and you don't need to do Norwegian death intervals every Saturday to reap the benefits.

Get your heart rate up regularly. Lift heavy things. Track your performance over time with simple, repeatable tests. If you're getting fitter by any reasonable measure, you're doing it right. It is all about effort.

The biggest jump in longevity comes from going from doing nothing to doing something. Everything after that is optimization. Start there.

And for the love of all things holy, stop letting your Apple Watch give you an existential crisis every time it updates your VO2 max estimate. That number is about as reliable as a gym bro's squat depth. (Studies have shown wrist-based VO2 max readings can be off by 20% or more compared to lab tests).

References & Further Reading

• Peter Attia, Outlive: The Science and Art of Longevity (2023)

• Alex Hutchinson, Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance (2018); Sweat Science column at Outside Online

• Barbell Medicine Podcast, Episode #391: "VO2 Max vs. Cardiorespiratory Fitness, GLP-1 Costs, and the 10,000-Step Myth" (March 2026)

• Mandsager et al., "Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults," JAMA Network Open (2018)

• Eric Topol on cardiorespiratory fitness measurement discrepancies

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