How does Apple health calculate vo2 max?


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Page last updated: 28/09/2022

How does Apple health calculate vo2 max?

In this guide, we will discuss How does Apple health calculate vo2 max, what this metric means and additional things to consider in regards to the metric VO2 max.

How does Apple health calculate vo2 max?

If you wonder, How does Apple Watch calculate VO2 Max? Your Apple Watch will calculate VO2 Max score via your Heart rate using the built-in Heart rate monitor. However, to get an accurate measure of VO2 Max, you may need to wear a mask since it is the only way to know for sure how much oxygen is going in and out of your lungs. 

It seems that this metric is very important for many Apple Health users since it will let you know about your aerobic fitness. However, consider that Apple Watch has also some other insightful metrics that could be very insightful on your overall health. One of the most interesting must be the VO2 Max, which is the ultimate test for your aerobic fitness. 

Moreover, if you play sports or you are into fitness, you may want to check this metric out. Here is a guide on what you need to know about VO2 Max measured on your Apple Watch. As indicated by

“As for the VO2 Max capability, it will estimate that value, which is considered a strong predictor of overall health (but can be hard to measure outside of specialized clinics) using the Watch’s motion sensor and heart rate sensor. Later this year, a feature will be added allowing users to be notified about a drop in VO2 Max”.

What is VO2 max?

“VO2 max is a measurement of the amount of oxygen from the air you breathe into your lungs that is then transported by your bloodstream to your muscles, where it is converted into energy during a workout (”. Moreover, if we analyze this metric, we would find that the ‘V’ stands for Volume and it is measured in litres per minute, which ultimately means the volume of oxygen you breath in a minute. 

However, Apple uses mL (kg x min), which means millilitres of oxygen per kilogram of body mass per minute. Taking into consideration your weight makes perfect sense since someone larger will need to consume more oxygen than someone smaller.

Predicted VO2 Max

As we have discussed, to accurately measure VO2, you may need to wear a face mask but since your Apple Watch doesn’t have the option to do so by being worn on your wrist, a ‘predicted VO2 max’ metric is estimated.

But are these predictions accurate? The relationship between heart rate and VO2 max is not exactly settled and it may vary from one person to the other, meaning VO2 max may not be very accurate. Moreover, this prediction depends on your Apple Watch’s heart rate monitor and while it is said to be very good, it is not error-free.

Finally, we need to consider how some factors may affect the accuracy of this metric such as genetics, training habits, age, gender and body composition. According to

“Structurally speaking, there are three components to the VO2 Max Puzzle. How much-oxygenated blood your heart can pump, How much of it reaches your muscles, and finally how much of it is actually utilized by your muscles”.

How does Apple health calculate vo2 max?

How can I check my VO2 max in the app?

You may not be able to check VO2 max on the watch itself but it may log still log your VO2 max. To see the data, you must use the Health app on your iPhone and simply tap on Health Data> Activity and scroll until you find it. If you have readings from the last 30 days, they will be highlighted in a big orange box. 

However, if you don’t see any VO2 data displayed, it may be languishing at the bottom of the list under the ‘No Recorded Data’ section.

Why is there no VO2 max data in the Health app?

According to, “If you can’t find any VO2 max readings in the Health app, that is probably because you have not yet logged the right kind of workouts with your watch. Only two workout types can produce an estimated VO2 max on Apple Watch: Outdoor Walk and Outdoor Run”.

Apple Watch Heart Rate Sensor

As discussed, the Apple Watch uses your Heart Rate to determine VO2 max. The heart rate monitor uses a green LED light paired with light-sensitive photodiodes to detect the amount of blood that is currently flowing through your wrist.

However, the optical heart rate sensor may also use infrared light. For instance, the Apple Watch Series 4 or later also have built-in electrodes in the Digital Crown and the back of the device. They can measure the electrical signals across your heart and if you place your finger on the digital crown, it will create a closed circuit between your heart and both arms which ends up capturing the electrical impulses across your chest. Your Apple Watch can measure heart rate between 30 to 210 beats per minute. 

How to improve your VO2 max?

The VO2 max is believed to be determined by a series of factors such as genetics and fitness level. Athletes are blessed with good genetics but anyone can increase their VO2 with the proper training. 

If you would like to compare typical VO2 max levels, there are some reference figures and charts but what is normal for someone may be completely different for another person, so it is recommended to focus on your progress rather than comparing with other people. For instance, the VO2 max score for untrained but healthy men is around 37.9 and for untrained women, it is 27.6 across all age groups. 

Moreover, to train your VO2 max, you need to workout at sufficient intensity to reach your anaerobic threshold. This is said to be the point where you won’t be able to sustain your workout with just your aerobic system and you may know when your body has approached this threshold since you may feel out of breath and a burning sensation in your muscles. 

Be careful

Sure, you may want to push yourself to the maximum possible and you’d want to increase intensity but be careful if you are not used to it. Moreover, if you make sudden changes to the level of exertion you subject your body to can result in an injury but if you are in doubt of what you could or couldn’t do, check with your physician first. 

If you are into fitness or you are starting your fitness journey, consider some (or all) of the included health and fitness metrics could potentially be used to train for a marathon or to fulfil your weight loss goals.

But, why is this measurement interesting? Well, the key to endurance in sports and other physical activities is said to rely on the ability to maintain a high intensity of effort for a long period of time. For instance, running at a good pace for a few yards is well, but that is not going to be of much use if you are planning on running a marathon. 

Your body uses different energy systems and this is the reason why you may not be able to maintain a fast pace for very long. Walking or jogging, which are considered low-intensity workouts, are easy to sustain for a long time because they rely on your aerobic endurance. Meaning that it is fueled mostly by the oxygen you breathe when you are exercising.

Why is this blog about How does Apple health calculate vo2 max important?

This blog about How does Apple Health calculate VO2 max has been very useful since contrary to what one might think, there is no need for a mask to measure VO2 max. However, many questions arise about the accuracy of the measurement since it uses heartbeat instead of measuring the amount of air that goes in and out of your lungs during a determined amount of time.

Finally, it is important to be careful if you intend to improve your VO2 max since forcing yourself into activities that require a lot of effort, all of a sudden, will actually be detrimental for your health and it will increase the risk of injury. 

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