Amazfit T-Rex Ultra 2 firmware adds waypoint metrics and heart rate zones

Zepp Health has released software version 4.8.3.5 for the Amazfit T-Rex Ultra 2, with the update dated May 8, 2026. It adds clearer workout data, improves route navigation behaviour and tweaks the VO2 Max algorithm for better accuracy.

The update focuses mostly on outdoor use, which fits the positioning of the T-Rex Ultra 2. This is a watch built around route guidance, rugged design and longer training sessions where small software details can make a noticeable difference.

Better workout data while training

For starters, users will now get a heart rate zone display during workouts. It can be enabled from Workout, Workout Settings, Data Pages and Heart Rate Zone. That should make effort-based training easier to follow during structured sessions. Instead of relying only on pace or heart rate numbers, users can see their current zone more clearly while they train.

The VO2 Max algorithm has been improved. The changelog does not go into detail, so it is difficult to know how much this will affect individual users.

Zepp Health has also added new workout data items for route-based activities. The watch can now show remaining distance, remaining ascent and remaining descent to the next waypoint and the final destination.

Route navigation gets cleaner

As far as navigation, the update improves turn-by-turn reminders. Zepp Health says it has optimized the sensitivity of those alerts, which should help reduce awkward timing when following a route.

Good navigation depends on alert timing. A reminder that arrives too late can send you past a turn, while one that triggers too often becomes distracting.

The company has also adjusted navigation-related text, including starting point settings and the arrival at destination page. These are interface refinements rather than major new features, but they matter when using a watch outdoors and trying to read guidance at a glance.

Track page interaction during workouts has also been improved. When entering edit mode, the touchscreen now activates directly, which should make mid-workout adjustments feel less clunky.

One other thing we spotted in our teardown of the APK of the latest Zepp Health app are direct route imports from Strava. But this is not live yet, hopefully it will be coming in the future.

A sensible update

Overall, software version 4.8.3.5 looks like a sensible update for the Amazfit T-Rex Ultra 2. It does not try to reinvent the watch, but it improves the outdoor and training tools that owners are most likely to use.

For users who rely on route navigation, waypoint data and effort-based training, this is worth installing when it appears in the Zepp app. As always, this is a gradual rollout.