# When Zwift sends the workout to Garmin connect, will it update my VO2, Lactate, FTP etc on my Forerunner 965?

**URL:** <https://forums.zwift.com/t/when-zwift-sends-the-workout-to-garmin-connect-will-it-update-my-vo2-lactate-ftp-etc-on-my-forerunner-965/606135>\
**Category:** General Discussion\
**Created:** [April 29, 2023, 11:11am UTC](https://forums.zwift.com/t/when-zwift-sends-the-workout-to-garmin-connect-will-it-update-my-vo2-lactate-ftp-etc-on-my-forerunner-965/606135 "2023-04-29T11:11:38Z")\
**Posts on this page:** 5\
**Page:** 2

<div class="post-metadata">

**Author:** ![gloscherrybomb](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/gloscherrybomb/32/493046_2.png) [@gloscherrybomb](https://forums.zwift.com/u/gloscherrybomb)\
**Post date:** [May 1, 2023, 8:00am UTC](https://forums.zwift.com/t/when-zwift-sends-the-workout-to-garmin-connect-will-it-update-my-vo2-lactate-ftp-etc-on-my-forerunner-965/606135/21 "2023-05-01T08:00:21Z")

</div>

There is nothing special about fit files that come from a garmin device, zwift, or anywhere else.

Garmin determines what it does with the file based on one single field in the file, which is the device. This has to come from a predetermined Garmin list of supported devices (which includes things like ‘other’ or ‘testing’).

Garmin recently expanded the list of supported devices to include more software platforms, such as trainerroad. Zwift is, also, included. All these supported devices work for the firstbeat algorithms (the challenges is a different story).

Changing the device in fitfiletools simply changes this value in the fitfile, for example if you take a fit file from a wahoo elemnt bolt and change the device to Tacx\_Smart\_Bike it now works for TSS, NP, training load, acute load, training readiness etc etc.

---

<div class="post-metadata">

**Author:** ![D\_I](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/d_i/32/481369_2.png) [@D\_I](https://forums.zwift.com/u/D_I)\
**Post date:** [May 1, 2023, 8:24am UTC](https://forums.zwift.com/t/when-zwift-sends-the-workout-to-garmin-connect-will-it-update-my-vo2-lactate-ftp-etc-on-my-forerunner-965/606135/22 "2023-05-01T08:24:25Z")

</div>

A few people on DCRainmakers blog and YouTube have said that TSS and IF currently don’t work when recording with just zwift.

Have you seeing updates to your TSS and IF with just using zwift?

---

<div class="post-metadata">

**Author:** ![gloscherrybomb](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/gloscherrybomb/32/493046_2.png) [@gloscherrybomb](https://forums.zwift.com/u/gloscherrybomb)\
**Post date:** [May 1, 2023, 12:05pm UTC](https://forums.zwift.com/t/when-zwift-sends-the-workout-to-garmin-connect-will-it-update-my-vo2-lactate-ftp-etc-on-my-forerunner-965/606135/23 "2023-05-01T12:05:27Z")

</div>

[![](https://global.discourse-cdn.com/gozwift/original/4X/8/4/5/8453115ab6fe8581b7d69656c1273681810d1568.jpeg "Garmin Training Effect: Now Calculated Directly From 3rd Parties (Zwift/TrainerRoad/etc)") ](https://www.youtube.com/watch?v=PfS3Dm41sVc)

Its easy to test using Garmin Connect on the Web. Use fitfiletools to change the device between different options, upload it to GC and look at how the metrics change between the different options.

---

<div class="post-metadata">

**Author:** ![Michael\_Rosenthal](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/michael_rosenthal/32/378145_2.png) [@Michael\_Rosenthal](https://forums.zwift.com/u/Michael_Rosenthal)\
**Post date:** [May 1, 2023, 12:16pm UTC](https://forums.zwift.com/t/when-zwift-sends-the-workout-to-garmin-connect-will-it-update-my-vo2-lactate-ftp-etc-on-my-forerunner-965/606135/24 "2023-05-01T12:16:34Z")

</div>

No. When just using Zwift, I get exercise load, but not IF or TSS.

---

<div class="post-metadata">

**Author:** ![D\_I](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/d_i/32/481369_2.png) [@D\_I](https://forums.zwift.com/u/D_I)\
**Post date:** [May 3, 2023, 11:52am UTC](https://forums.zwift.com/t/when-zwift-sends-the-workout-to-garmin-connect-will-it-update-my-vo2-lactate-ftp-etc-on-my-forerunner-965/606135/25 "2023-05-03T11:52:31Z")

</div>

Are TSS and IF metrics important?

How do they factor into Firstbeat metrics (if at all)?

[Previous page](https://forums.zwift.com/t/when-zwift-sends-the-workout-to-garmin-connect-will-it-update-my-vo2-lactate-ftp-etc-on-my-forerunner-965/606135.md?page=1)