Guide

Get Zwift power and Garmin Training Effect in one activity

Garmin's training metrics — Training Effect, Body Battery, Stamina, recovery time — only come from activities recorded on the Garmin itself. Zwift's power, cadence, and virtual routes only exist in the Zwift file. You don't have to pick one: record on both and merge.

The problem with choosing one device

Ride Zwift without the Garmin recording and your watch's training status, load, and Body Battery miss the whole workout — for many riders that's the data they bought the watch for. Record only on the Garmin and you keep the physiology but lose the trainer's power and cadence (unless everything is paired twice) and always lose the Watopia route, in-game distance, and elevation. Recording on both captures everything — split across two files that show up as duplicates on Strava.

The dual-recording setup

1. Pair your trainer and sensors to Zwift as usual.
2. Start an indoor-bike activity on your Garmin watch or Edge at the same time. Pairing the same cadence sensor, heart-rate strap, or power source to both devices helps later — a shared signal lets the merge align the timelines precisely.
3. Ride. Save both activities when you finish.

Merge the two files

Export both FIT files and drop them into BikeSync: the Garmin file in slot A, the Zwift file in slot B. The merged activity keeps from each side:

• From the Garmin (file A): heart rate, temperature, Body Battery, Stamina, Training Effect, laps, calories, and the device identity — so platforms treat it as a Garmin-recorded ride.
• From Zwift (file B): power, cadence, speed, distance, elevation, and the virtual GPS route.

Everything runs in your browser — no account, no uploads — and the result is one .fit file ready for Garmin Connect, Strava, or TrainingPeaks.

One honest caveat

Metrics your watch computes after the ride from its own recording (like training status trends) are based on what the watch saw — merging doesn't rewrite history inside Garmin's ecosystem. What the merge gives you is a single complete activity file, with the watch's device-recorded values preserved, everywhere you upload it.