Apple Watch Calculates VO2 Max in watchOS 4 Beta


Apple Watch will soon be calculating VO2 max measurements in watchOS 4. What is a VO2 max score? Here’s a simple explanation:

VO2max stands for maximal oxygen uptake and refers to the amount of oxygen your body is capable of utilizing in one minute. It is a measure of your capacity for aerobic work and can be a predictor of your potential as an endurance athlete.

VO2 max scores are valuable for endurance athletes to measure their aerobic potential and to track training progress.

When iFixit did a tear down of Apple Watch back in 2015, they noted “Apple’s heart rate monitor is actually a plethysmograph—it looks and acts like a pulse oximeter, but Apple isn’t claiming it can measure your blood oxygen level.”

A pulse oximeter measures oxygen levels in the blood, but Apple disabled this in Apple Watch, for reasons unknown.

But now it appears Apple is calculating VO2 max scores for watchOS 4 beta testers when they use the Workout app. The VO2 max score is viewable in the Health app, as noted by a user on Reddit.

Apple watch v02 max

Another Reddit user noted the Health app for VO2 max reads:

“Values stored from Apple Watch represent a predicted VO2 Max, and are captured during intense Outdoor Walk or moderate to intense Outdoor Run sessions in the Workout app that are at least 20 minutes in length and maintain a persistent heart rate throughout the workout session.”

So VO2 max calculated by Apple Watch is actually estimated based on your heart rate, but knowing Apple, it’s probably going to be pretty accurate.

Apple Watch Series 3 is rumoured to launch in the second half of 2017, and it could come with LTE; many probably suspect the next version would include more sensors for improved health and fitness tracking.


  • John Scarfone

    It appears to be there for some and not others on this beta.

  • From people who have used the Workout app on a run, it seems to show up.

  • John Scarfone

    Unfortunately not for me! 🙁

  • Nicolas Gosselin

    I’m the guy who found it and posted it on Reddit, my 2 minutes of fame. LOL

  • I knew it was someone in Canada on Rogers! Cool find.

  • Nicolas G.

    It was totally an accident, I was looking at the health app then I saw the VO2 Max.

  • Mario Gaucher

    a few Intense Outdoor walks last week (especially this weekend – 2 hours trekking)… still nothing showing in the VO2 Max section.
    I don’t know if those really qualified as intense… but surely those were intense for me! 😉

  • Nicolas G.

    Did you bring your iPhone with you, I’ve read that need it for the VO2 Max to register. I always bring my phone with me.

  • Mario Gaucher

    I also always have my iPhone with me… so I don’t see why it wouldn’t register (unless this data is not available for outdoor walks).

  • mark hoskins

    I would think you’d need to do at least a mile run on the road to register a vo2max reading.

  • Mario Gaucher

    I didn’t come back… but I’m getting the VO2 Max value for my walks…

    that said, it needs to be a high intensity walk to get the VO2 Max… like I’m doing +/- 10 minutes minimum per km and I have the VO2 Max.
    If I go for a lower walk… 13-15 minutes per km… I don’t get it.

  • Ball Bearing

    I’m getting the VO2 Max readings without my phone when I swim or kayak without the phone using the iWatch 2. Typically training for 40 – 80 mins. For the Paddling / Kayak I use the Outdoor Run Setting. Hope this helps.

  • Ball Bearing

    Same for me