Cardio Fitness doesn't have Apple Watch as a data source

My VO2 max hadn’t worked since September 2020. I followed the above suggestions about privacy/location services/fitness tracking/heart rate/not on power save mode/etc. Then I went for a 20+ minute walk outdoors (recorded an outdoor walk workout) WITHOUT my phone. That finally forced my Apple Watch to show up as a data source in VO2 max and I got a reading! I had tried this yesterday with my phone in my pocket on the walk and it didn’t work. We’ll see moving forward if it continues to give me readings on outdoor walks/runs/hikes with my phone and watch on, now that it is finally reading data from my watch. 🤞

Just carry out two outside walks (over 20minutes each) and the data source will be updated as your Apple Watch after 24 hours.

Sie müssen Training APP auf Watch "Stromsparmodus" abschalten und denn einen 20min Training im Freien absolvieren. Sonst wird Herzfrequenz während Training nicht gemessen.

My solution:

Had same symptoms like most above and tryed everything recommended.

Only after I renamed my watch the VO2max was calculated again. For sure after the last run.

Just in the event you didn’t see my post. The cardio fitness started working for me when I did a walk of over 20 minutes without taking my phone with me.

" I have never had one cardio fitness reading yet. "

I asked because it's not clear with a lot of people here if they are talking about the new feature or about the VO2 Max readings in general. I assume you mean you have never gotten any VO2 Max

readings since you got the watch?

"average pace of 14:09 per mile"

The algorithm isn't going to care about your pace. The only thing important, particularly before the latest update, was the intensity of the work out. If it didn't reach a fairly high intensity, no reading. It was my experience prior to the update that only pretty intense running generated a reading, not walking.It appears however that this is changed and Apple says readings will be generated from lower intensity activities

"No data source. "

There's a lot of confusion about this year. If you don't have data the watch won't be listed as a data source. That only appears after the first reading.

Hello Osugrad85, you are right, at first i tried everything to make watch a “source” manually for Vo2, even ended up deleting data for some old watches in trial and error...however you can always “prioritize the source for heartbeat(not Vo2max”) by pressing edit on top right corner and moving current watch as a source up, as It is an important calculation parameter for Vo2max,

what i observed is, Vo2max selected data source automatically after 2 workouts, after doing steps mentioned in my earlier post.

If you're talking about cardio fitness I can only give you the benefit of my experience. After I bought my Apple Watch six and installed the update the date it started showing up after about four days. I ended up re-pairing the watch and after that I think I took only two days. Based on what I have seen here I am guessing that it shouldn't take longer than a week or so, assuming all the correct conditions are met.

The only thing I'm really sure of is that the watch won't show up as a data source until it writes the first data. The part about it taking time is just a theory but that was my experience. I actually had to re-pair the watch and the second time it also took some days which supports the theory.

Anyway, I hope I'm right and you get your data soon. Let me know because I will be curious.

I'm pretty sure he is confused about something. Your watch will not show up as a data source for VO2max until the first time it writes data. In other words, it can't be a source until it is a source. :-)

It is a current limitation of the Apple Watch but if it's that important to you, is there something stopping you from walking or running outside for 20 minutes in addition to what other activity you do? Just asking?

Also, the Apple product announcements and support for the watch pretty clearly identify that limitation:

"Apple Watch already estimates average and higher levels of VO2 max during vigorous outdoor walks, runs, or hikes, "

OK, I know you have said you tried everything but does that include reinstalling the watch as brand new meaning not using a back up?

Well, my husband finally got data to show up in cardio fitness. He did 5 ourdoor walks, all under two miles each, average pace 20/mph, half of it through the woods, so uneven. My next move will be to do the same and see if that fixes things for me. It's absurd for Apple to make the requirement to be a 20 minute run at 10 mph. We are in our 70's and very active and fit, but running stopped a long time ago when knees said ENOUGH. I do a lot of core and strength training now, plus walking/hiking. For "" to have any value at all, it needs to measure more than a 10 mph run.

I wish people would read through these threads. I pointed out multiple times that your watch won't show up as a data source until the first time it writes Cardio Fitness data. That is normal behavior for all health metrics.

So, the important question is how long have you had the watch?

unless you both have exactly the same activity patterns, there may very well may be a reason. It took my new watch about seven days before the data started showing up so I would give it a little while longer before you conclude there is an issue. I suspect there is some kind of baseline that is needed before the first computation is made.