What happened in Apple Watch data in strava

Hi Jane - I'm not the OP, but a Google search brought me here, and I appreciate your reply.

I have recently tried switching to a direct sync of activities from my Apple Watch to Strava (I previously was syncing via a third party service). For each of my last four runs, I have shown below three elevation readings: the elevation recorded by the Apple Watch shown in the Apple Fitness workout (A); and the two elevation readings you can switch between in the Strava activity - "use device data" (B) and "use Strava data" (C).

(A) Apple Watch 55m, (B) "use device data" 132m, (C) "use Strava data" 56m

(A) 23m (B) 83m (C) 23m

(A) 27m (B) 101m (C) 31m

(A) 829m (B) 963m (C) 798m

 So two things:

1. As there is the option to switch from "device data" to "Strava data", it appears that Strava does use the elevation data from the Apple Watch's barometric altimeter? Maybe this has changed since your July reply?

2. Knowing the terrain, I am pretty sure the (A) and (C) results are closest to the actual elevation gain, and they agree with each other reasonably well in these samples. So there seems to be an issue with whatever smoothing/adjustment is happening when Strava uses the Apple Watch's elevation data - it is consistently higher than it should be.

I see it very similarly. I regret that I use the products of TOP companies (Apple, Strava) and have to constantly correct the "elevation gain" via the "Adjust elevation" button in Strava. Despite the fact that the AWU measured the data practically accurately.

I would appreciate information on when the problem will be solved. It has worked perfectly for many years.

Especially for activities with a changing altitude profile, the altitude meters do not correspond to reality at all. Although I am a paying Strava member, I now have to pay for another app to transfer the data from the Apple Watch correctly. This is very annoying. 

When will the problem be solved?

Same here, I have been doing the same walk with my dog for 3 years with my Apple Watch 4 which did not have a barometric altimeter and always got around 40ft(12m) of gain, it is flat here in New Jersey. I got an Apple Watch 9 in March which has the barometric altimeter and now get an average of 427(130m) of gain!!! This happens every walk and it is insane. I use the Apple watch Workout app to record my walks and the Apple Health app to sync my data to Strava. The workout app is correctly recording the gain but when it transfers to Strava is gets convoluted.

Activities recorded with an Apple Watch Ultra 2 do not have their Apple elevation data applied – they seem to automatically (and irrevocably) get the Strava-derived data, with no "Adjust Elevation" option. As someone who chases Elevation Challenge numbers every month, the "who knows what Strava will make of THIS run" element is really frustrating.

Also, @Jane11, "We don't currently use the elevation data collected by your Apple Watch's barometric altimeter on Strava" seems in direct opposition to what Strava's own Elevation FAQ says: 

"We generally consider the data from barometric altimeters to be of higher quality than the data derived from GPS signals and prefer that when processing activities"

I recognize that there might be some technical reason why Apple Watch activities get their elevation data paved over with Strava's, but the way it feels right now is more like "we love barometric altimeter data! Just not yours, Apple Watch users!"

This is my issue too! I initially thought it was just slight gps misreadings in tight canyons (a small lateral error can be a big elevation change when you’re on a ridge). But I don’t understand the three different readings. It seems like Strava is reading raw barometric pressure and calculating it differently (and significantly incorrectly) from Apple?