What Is VO2 Max and Why Should You Care?
You can lift weights, hit your workouts consistently, and feel like you're in pretty good shape but how fit is your body on the inside? One number can tell us a lot about how efficiently your heart, lungs, and muscles work together... So, what exactly is VO₂ max, why does it matter so much, and, most importantly can you improve it? Let’s get into it.
Maddy DiCioccio
8/23/20264 min read
What Is VO2 Max and Why Should You Care?
When we talk about improving fitness, we usually hear about getting stronger, building muscle, losing body fat, or improving endurance. But there’s another measurement that can tell us a lot about our overall fitness and cardiovascular health: VO2 max. People typically think this only applies to elite runners / athletes for it to "matter" but that's very untrue; everyone should know their baseline.
What Exactly Is VO2Max?
VO2 max stands for maximal oxygen uptake. Aka, it measures the maximum amount of oxygen your body can take in, transport, and use during intense exercise.
Think about what happens when you start exercising..your muscles need more energy, which means they need more oxygen. Your heart beats faster, your breathing increases, and your cardiovascular system works harder to deliver oxygen-rich blood to your working muscles. Your VO2 max gives us an idea of how efficiently your heart, lungs, blood vessels, and muscles work together when the demand gets high. Generally speeaking, a higher VO2 max means your body is better equipped to use oxygen during exercise.
Why does VO2 max matter?
1. It tells us how well your cardiovascular fitness is:
It is one of the most useful measurements of cardiorespiratory fitness. It tells us much more than simply whether you can run a mile without stopping. A stronger aerobic system allows your heart to pump blood more efficiently and helps your muscles utilize oxygen effectively. This can translate to better endurance, improved work capacity, and less fatigue during physical activity.
2. It can improve your overall training performance:
Even if your main goal is strength or body composition, your cardiovascular fitness still matters. A better aerobic base can help you:
Recover faster between sets
Maintain your performance during longer workouts
Handle higher training volumes
Recover better between training sessions
Perform better during conditioning workouts
Feel less exhausted during everyday activities (ADL's)
For athletes participating in events that combine strength and endurance i.e.; HYROX, CrossFit, Ironman's, running, cycling, or other hybrid-style training...VO2 max becomes even more relevant and important to focus on.
The better your body is at delivering and using oxygen, the more work you can potentially sustain before fatigue starts taking over.
3. It matters outside of the gym as well:
This is one of the biggest reasons I think people should care about cardiovascular fitness!! Training isn’t only about what your body looks like; we also want to build a body that functions well for a long time. Higher levels of cardiorespiratory fitness are strongly associated with better long-term health outcomes. Improving your aerobic fitness can support heart health, metabolic health, physical independence, and your ability to tolerate everyday physical demands as you age.
You don't need the VO2 max of an Olympic athlete. The goal is simply to maintain, and ideally improve your cardiovascular fitness over time.
So...how do we improve this??
VO2 max is completely "trainable", however, genetics, age, sex, and training history all influence your starting point; but consistent cardiovascular training can improve your aerobic fitness.
This doesn't mean you need to train for hours on end each day you just need to have a well-rounded approach that includes all HR zone trainings. Ideally, stationary, "EZ" cardio mixed with intervals, and higher intensities.
For example, zone 2 training builds your aerobic base: think steady cycling, jogging, rowing, incline walking, or another form of cardio where you're working but can maintain the effort for an extended period. Higher-intensity intervals challenge your cardiovascular system closer to its upper limits. These might include harder efforts on a treadmill, bike, rower, or Ski-Erg followed by periods of recovery. You don't need every workout to leave you completely exhausted. In fact, constantly going as hard as possible isn't necessarily the best way to improve your fitness. Consistency and progressive overload apply to cardiovascular training just like they do to strength training.
How is VO2 max measured?
The most accurate method is a lab VO2 max test, where you exercise while wearing a mask that measures the oxygen you consume and the carbon dioxide you produce as the intensity gradually increases. This is typically not available to the average person / costs a good deal of moola in the process. SO, the second best way is to get an estimated VO2 max via a device that most people have access to; i.e., different fitness watches and other wearable devices can also provide an estimated VO2 max based on things like heart rate, pace, and workout data. These numbers obviously aren't the same as a laboratory measurement but they can still be useful for following trends over time.
Instead of obsessing over one number, pay attention to the bigger picture: Is your cardiovascular fitness improving Can you maintain a faster pace at the same effort? Does your heart rate recover more quickly? Can you work longer before becoming fatigued? Are workouts that used to feel difficult starting to feel easier? Those improvements matter!!
In summary:
VO2 max isn't just a number for runners. It's one piece of the bigger picture of building a stronger, healthier, more capable body. We spend a lot of time focusing on how much weight we can lift, what the scale says, or what we see in the mirror; but cardiovascular fitness deserves a place in the conversation too.
Build muscle. Get stronger. Train hard....BUT don't forget to train your heart, lungs, and aerobic system along the way. Fitness shouldn't just be about looking strong; it should be about building a body that can perform, recover, and continue showing up for you for years to come.