Persisting VO2 max update issue on watch

My Apple Watch SE second generation has stopped updating VO2 max data. The watch is running on the most up to date OS version, as is the phone it’s linked to. I have reviewed all settings relating to data sharing between the devices, performed numerous re-starts on both devices, and attempted manual data inputs for VO2 max to try and force an update, but none of these have worked to date. It appears my only remaining option is to do a factory reset, which I’m a little loathed to do as this may result in all previous run data being erased? Is there some obvious solution here that I’ve overlooked? Any guidance/advice would be much appreciated.

Apple Watch SE, watchOS 26

Posted on Dec 10, 2025 11:58 AM

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Question marked as Top-ranking reply

Posted on Dec 10, 2025 9:22 PM


To rule out a software issue, erase the watch and pair it again, setting it up as a new device. You will only lose your created Watch faces and may have to activate the cards in your Wallet app again.

Your Fitness data is saved in iCloud and will sync back.


Then recored an Outdoor Walk or Outdoor Run again and check the VO2 estimate.

Unpair and erase your Apple Watch - Apple Support

3 replies
Question marked as Top-ranking reply

Dec 10, 2025 9:22 PM in response to GlenLau


To rule out a software issue, erase the watch and pair it again, setting it up as a new device. You will only lose your created Watch faces and may have to activate the cards in your Wallet app again.

Your Fitness data is saved in iCloud and will sync back.


Then recored an Outdoor Walk or Outdoor Run again and check the VO2 estimate.

Unpair and erase your Apple Watch - Apple Support

Dec 12, 2025 10:48 AM in response to GlenLau

I don't think that this is a hardware issue, since the heart rate, distance and time are used to estimate your VO2max.

It may also take a couple of walking or running workouts to get a new VO2 estimate after resetting the watch.


Your watch is still set as a data source for Cardio Fitness?

Open the Health App -> Cardio Fitness -> Data Sources & Access -> Choose your watch -> Check the date and time when your watch last recorded VO2max.


Persisting VO2 max update issue on watch

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