Guide

Zwift power and Garmin Training Effect in one activity

Ride Zwift with your Garmin on your wrist and you get two half-complete activities: one with the power and the virtual course, one with the physiology. Before you decide whether that's worth the bother, it's worth being precise about what a Zwift ride does deliver to Garmin Connect on its own — because it's more than people assume, and the real gap is somewhere else.

What a synced Zwift ride does give you

With your Zwift and Garmin accounts linked and Physio TrueUp on, a Zwift activity arriving in Garmin Connect generally does count toward training load and training status, and feeds the longer-term figures built on them. You don't have to record on the watch to get that.

The caveat is that exactly which numbers show up varies by device, firmware and settings. That's why two riders with apparently identical setups report different results, and why it's worth checking your own device rather than trusting a forum thread.

What it can't give you, at all

Here's the real gap. These come from the watch sensing continuously on your wrist, not from an activity file, so no upload can produce them:

• Body Battery and its drain for the ride
• All-day stress and the recovery that follows a hard effort
• Respiration rate through the session
• HRV and the overnight metrics built on it

If you don't wear the watch during the ride, or you wear it but don't record, the session is a blank in that part of your data. For some riders that's irrelevant. If you track recovery and readiness seriously, it's the whole point of dual recording.

Intensity minutes: don't panic early

A common false alarm. Intensity minutes are not stored in an activity file — in the FIT profile, moderate and vigorous activity minutes exist only in daily monitoring messages, never in an activity session. Garmin Connect calculates them on its servers from your heart rate against your zones.

Two consequences. They can appear some time after the upload, so an activity that shows none immediately may well have them an hour later. And they depend on your own zone settings, so an easy ride that never leaves a low zone can legitimately earn none at all.

So: record on both, then merge

Dual recording gets you the wellness side from the watch and the power and route from Zwift. The price is two activities for one ride, and merging the files is what gets you back to one:

1. Export the Garmin file — it arrives as a zip — and get the Zwift file from zwift.com or your device.
2. Put the watch recording in slot A and the Zwift ride in slot B at bikesync.ninja, and merge.
3. Upload the merged file and delete the two originals, which also clears the Strava duplicate.

What survives the merge

With the watch file as the master, the merged activity keeps the things only the watch could produce — Training Effect, Stamina, respiration, Body Battery impact, heart rate, laps and calories — plus Intensity Factor and Training Stress Score where your device recorded them, since those travel in the session rather than being recalculated. Garmin Connect continues to list the merged activity as recorded by your watch, not as an import.

From the Zwift side the merged file takes power, cadence, speed, distance, elevation and the virtual route, and the summary figures backed by those — average and normalized power, total ascent, average speed — are recomputed so they describe what the activity actually contains.

One thing to set deliberately: if you run a power meter paired to the watch and want its numbers rather than the trainer's, open Field sources before merging and set power to file A. Everything else stays as the preset had it.

Is it worth it?

Honestly, not for everyone — and it's worth saying so. If your trainer and heart-rate strap are paired to both Zwift and your head unit, both files already contain much the same data, and the merge adds little beyond the route. If you don't follow Body Battery or recovery metrics, the synced Zwift ride on its own covers you.

It's worth it when the two recordings genuinely differ: the watch holding physiology the file can't carry, Zwift holding the power and the course. That's the case this was built for.