TL;DR: VO₂ max matters, but at PrimaryMD, we don’t let shiny metrics eclipse other meaningful and sustainable components of health and fitness.
VO₂ max, which, let’s face it, just sounds cool (though also calls to mind the “recently rebranded” in our modern age; i.e.: HBO max) has rightfully become a celebrated metric for fitness and longevity. It measures the maximum rate at which your lungs, heart, blood, and muscles can extract, transport, and utilize oxygen to produce ATP, the energy currency of cells, before relying on anaerobic systems (i.e. entering your “lactate threshold”). This single number encapsulates the efficiency of your aerobic metabolism, making it a powerful indicator of physical capability.
In other words, VO2 max offers a trackable, reliable metric of your cardiovascular health. With the advent of smartapps, like Apple’s iHealth, algorithms can spit out (questionably accurate) estimates of your VO2 max on demand. At PrimaryMD, we perform VO2 max assessments of every patient upon intake, because for 100 years it has been recognized as a brilliant distillation of human physiology into a quantifiable value.
First described by A.V. Hill and Lupton in 1923, VO₂ max is the point at which oxygen consumption plateaus despite increasing exercise intensity. Though it may be easier to think of VO2 max as a destination, instead of a static metric. Consider for a moment your skeletal muscles collectively make up a combustion engine in a sports car. When you floor the accelerator until the top end speed your engine is capable of achieving, you’ve hit your VO2 max.
It’s expressed in milliliters of oxygen per kilogram of body weight per minute (ml/kg/min). This has a few immediate and relevant implications. First is that, for most people, the less you weigh, the higher your VO2 max will be. Another relates to the variability of metabolism of certain types of cells, as not all cells are as efficient at energy expenditure. Fat cells have very low resting metabolic rates as they serve as reservoirs for energy. This means lowering your body fat percentage will also immediately increase your VO2 max.
Why might you want a higher VO2 max? A higher VO₂ max allows your muscles to work harder and longer before fatigue sets in due to lactate buildup. For context, the average American has a VO₂ max in the low 30s, while elite endurance athletes may reach 75 or higher, enabling them to perform at levels far beyond the norm.
In everyday life, most people rarely approach their VO₂ max unless severely deconditioned by illness or immobility. Even elite athletes can sustain it only briefly. Yet, VO₂ max remains significant because it predicts both athletic performance and functional capacity. For example, running a sub-7-minute mile typically requires a VO₂ max of 48–55 ml/kg/min, while a 4-minute mile demands values above 75. On the opposite end of the spectrum, someone with advanced chronic lung disease might have a VO2 max in the 12-15 range, which is nearly incompatible with life. These numbers highlight the vast differences in aerobic efficiency between individuals.
VO₂ max is more than a performance metric; it’s strongly correlated with health outcomes. The Aerobics Center Longitudinal Study found that higher VO₂ max levels are associated with reduced risks of cardiovascular disease, cancer, and all-cause mortality. The American Heart Association now recognizes cardiorespiratory fitness as a “vital sign,” noting that improving VO₂ max can lower physiological stress over time, potentially extending life.
As alluded to previously, the cultural prominence of VO₂ max has surged with wearable technology, such as Apple Watches and Garmin devices, which estimate VO₂ max and present it as a trackable goal. Fitness influencers and longevity experts have further amplified its appeal, often framing it as a key to a longer, healthier life .
However, the link between VO₂ max and longevity is not as straightforward as it seems. Many studies, including the influential 2018 Cleveland Clinic study, rely on estimated VO₂ max values derived from treadmill performance rather than direct measurements . This study, involving over 122,000 patients referred for clinical stress testing, found that those in the lowest fitness quartile had up to 80% higher mortality than the highest. But these participants were not healthy volunteers; many had suspected cardiovascular issues. Poor treadmill performance often reflected underlying disease—such as chest pain or shortness of breath—rather than just low aerobic fitness.
Recent research has further questioned the direct role of VO₂ max in longevity. A 2024 Mendelian randomization study published in The Journal of Clinical Endocrinology & Metabolism used genetic variants to explore whether VO₂ max causally affects longevity. The findings were striking: while VO₂ max is a strong predictor of mortality in observational studies, genetically predicted VO₂ max showed no association with longevity. This suggests that the correlation seen in earlier studies may stem from confounding factors—such as overall health, physical activity levels, body composition, or lifestyle choices—that influence both VO₂ max and lifespan, rather than VO₂ max directly causing longer life.
Just because high VO₂ max is associated with longer life at the population level doesn’t mean every individual must achieve a specific number to live longer. VO₂ max is a useful but incomplete measure. It fluctuates with age, training status, illness, and testing conditions. It also fails to capture other critical aspects of health, such as joint integrity, mental resilience, balance, or a sense of purpose, all ascertainable factors like these profoundly shape how we age.
The hype around VO₂ max, fueled by influencers and wearable tech, can lead to an unhealthy obsession with achieving elite-level numbers. This mindset risks harm, as pushing too hard to boost VO₂ max can result in overtraining, injuries like tendinopathy or stress fractures, and burnout. These consequences are all too common among patients who adopt unsustainable regimens to hit arbitrary fitness targets. VO₂ max represents a physiological ceiling, not a daily goal. Most of life—and most of a healthy lifespan—is lived well below this ceiling, in the realm of moderate, sustainable activity.
The pressure to compare oneself to others, whether elite athletes or peers on social media, can also distort perceptions of health. X posts from longevity enthusiasts sharing their VO₂ max stats can create unrealistic expectations, as seen in discussions on platforms like Reddit. At PrimaryMD, we counsel patients to avoid this trap, focusing instead on personalized, progressive fitness plans that prioritize long-term well-being over short-term metrics.
The true value of VO₂ max lies in its role as part of a broader health assessment, not as a standalone target. Improving VO₂ max through regular, moderate exercise—such as brisk walking, cycling, or swimming—can enhance aerobic capacity, strengthen the heart, and improve quality of life. But it’s equally important to nurture other pillars of health, including strength, mobility, mental well-being, and social connections. For some individuals, it’s great to include HIIT to target VO2 max.
At PrimaryMD, we guide patients to interpret VO₂ max in context, understanding its strengths and limitations. We emphasize incremental, sustainable improvements tailored to individual needs, ensuring that fitness enhances independence, joy, and purpose.
Fitness and longevity is not a competition or a quest for the highest score. It’s a lifelong relationship with your body, habits, and future self. While VO₂ max offers valuable insights into aerobic fitness, it’s not the ultimate measure of longevity. The best marker of success is your ability to keep doing what you love—whether that’s hiking, cycling, or it could be targeting training for increased cardiovascular fitness—for as long as possible.
By focusing on sustainable progress and a holistic view of health, you can harness the benefits of VO₂ max without falling into the pitfalls of optimization. At PrimaryMD, we’re here to support you on this journey, helping you build a healthier, happier future, one step at a time.