How to Check Apple Watch VO2 Max Accuracy

What to Know

  • VO2 max is the maximum volume of oxygen that your body consumes when exercising.
  • The Apple Watch VO2 max likely under/overestimates your VO2, so it is not 100% accurate.
  • You can check your VO2 max in the Heart section of the Health app on your iPhone.

If you're a health nut, the Apple Watch is the perfect device for you. The device is packed with a wealth of fitness-related features that are designed to help you meet your goals and stay in shape. One of the Apple Watch's many great features is its ability to measure your heart rate and blood oxygen level. As a part of this, it can also measure your VO2. But how accurate is the Apple Watch’s VO2 max reading? Let's find out.

Jump To:

What Is Apple Watch VO2 Max?

VO2 max refers to the maximum volume of oxygen your body consumes when you exercise. This measurement can help you better understand your health and physical fitness. Normally, your VO2 max is measured by wearing an oxygen mask while running on a treadmill. This method gives you the most accurate reading. Smart devices like the Apple Watch or Garmin smartwatches can also measure your VO2 max.

How Accurate Is Apple Watch VO2 Max?

The Apple Watch measures your VO2 max by gathering data from workouts like Outdoor Walks and Runs, or Hiking. If you don't use these types of workouts very often, you might not be able to get an accurate reading. For more ways to stay healthy with your Apple Watch, be sure to check out our free Tip of the Day newsletter.

iPhone Life
Discover your iPhone's hidden features
Get a daily tip (with screenshots and clear instructions) so you can master your iPhone in just one minute a day.

It is also important to keep in mind that the most accurate way of getting this reading is with an oxygen mask, so the Apple Watch will never be quite as accurate. In most cases, the Apple Watch is likely underestimating (or even overestimating, as Neal Templin at Barron's found out) your actual VO2 max.

How to Check Apple Watch VO2 Max

You can your Apple VO2 max in the Health app on your iPhone. Here's how to see your Apple Watch VO2 max:

  1. Open the Health app.

    iphone home screen with a red box around health app
  2. Tap Browse.

    iphone health app with a red box around browse tab
  3. Tap Heart.

    iphone health app with a red box around heart
  4. Scroll down to Cardio Fitness.

    iphone health app heart screen with a red box around cardio fitness
  5. You'll see a measurement of your VO2 max.

    iphone health app cardio fitness screen with a red box around vo2 max level

So is the Apple Watch VO2 max accurate? Now you know the accuracy and how to check your VO2 max on your Apple Watch at any time. Next, find out how to use heart rate workout zones on the Apple Watch.


  • Can you add workouts to Apple Watch manually? If you ever forget to wear your Apple Watch during a workout or if you just forgot to start the workout, you can easily record it using the Health app. Find out how to manually add a workout to Apple Watch.
  • Can you add data to the Health app? If you find that your Apple Watch didn't record data accurately, you can always adjust it. Check out our article on how to manually add data to the Health app.
  • How do you start a workout on Apple Watch? There are many ways to start a workout on your Apple Watch. You can do so in the workout app, or you can ask Siri. Our article on how to start a workout on Apple Watch with Siri has all the details you need to start exercising.
  • How do you see Apple Watch workout history? You can view previous workouts in the Fitness app on your iPhone. Find out how to use Apple Watch to see past workouts.
Master your iPhone in one minute a day: Sign up here to get our FREE Tip of the Day delivered right to your inbox.


Author Details

Rhett Intriago's picture

Author Details

Rhett Intriago

Rhett Intriago is a Feature Writer at iPhone Life, offering his expertise in all things iPhone, Apple Watch, and AirPods. He enjoys writing on topics related to maintaining privacy in a digital world, as well as iPhone security. He’s been a tech enthusiast all his life, with experiences ranging from jailbreaking his iPhone to building his own gaming PC.

Despite his disdain for the beach, Rhett is based in Florida. In his free time, he enjoys playing the latest games, spoiling his cats, or discovering new places with his wife, Kyla.