Amazfit T-Rex Ultra in the test: This smartwatch is real competition for Garmin

While Polar, Garmin and Co. offer their dedicated smartwatches for outdoor enthusiasts at prices in the mid to high three-digit euro range, the Chinese manufacturer Amazfit is trying to find a cost-effective alternative. The Amazfit T-Rex 2 (test report) was able to convince in our test as an excellent smartwatch for price-conscious athletes. With the T-Rex Ultra, the company is now launching a top version of the outdoor watch. We took a closer look at the new edition and compared it with the conventional T-Rex. In our test, we clarify whether and for whom an upgrade to the Ultra model is worthwhile.

As already mentioned, the Amazfit T-Rex Ultra is aimed directly at outdoor lovers – and you can see that in the design of the watch. It comes in the classic, bulky military look, which can look a bit clumsy on narrow wrists. Nevertheless, the look is convincing, although the watch itself doesn’t bother you on the wrist (this also applies to sleeping).

The T-Rex Ultra comes with a silicone strap, while a USB charging cable and instruction manual are also included in the box. The case itself is made of polycarbonate and is water resistant to 10 ATM. It also has a diving function for open water diving up to 30 meters deep. Amazfit advertises that the watch has been certified according to military standards and should be shockproof and dustproof. The T-Rex Ultra is operated both via buttons on the side of the housing and via a touchscreen. Both work smoothly and intuitively – we did not notice any delays in input in the test. After all, the display works as an always-on display, which we can also deactivate in favor of the battery life. Then it only lights up when we raise our arm to look at the clock.

Setting up the T-Rex Ultra does not differ from that of the conventional T-Rex: We download the Zepp app, create a customer account and then connect the T-Rex Ultra to our smartphone according to the instructions on the screen. This only takes a few minutes and worked without any problems in our test.

As a smart sports watch, the T-Rex Ultra has various options for tracking activities. If you want, you can have the steps taken displayed directly on the always-on display of the watch. If desired, we can also activate 24-hour heart rate monitoring, whereby we receive a warning if the heart rate is unusually high. Heart rate variability is also measured and used to calculate our stress level.

Anyone who is often out and about in the mountains will not only benefit from the integrated GPS tracking, but also from an altitude barometer, air pressure gauge and blood oxygen measurement. If we are traveling at high altitude, the watch will automatically inform us as soon as our blood oxygen levels drop to alarming or dangerous levels. The altimeter worked reliably in our test, as did the measurement of blood oxygen saturation. The measured values ​​corresponded to the geographical conditions or the results of our control device. The GPS also worked very reliably and only deviated slightly from the actual route in areas with poor satellite coverage. Particularly useful on top of that: The T-Rex Ultra has the option of synchronizing offline maps. This allows us to determine our location at any time, even if we do not have a cell phone network.

The T-Rex Ultra also uses all recorded activities and heart rate data to calculate the so-called Physical Activity Index (PAI). This index uses an algorithm to evaluate our state of health and gives users a rough guide to their general well-being. The informative value of this feature is limited, but it offers good support in dealing with your own health in the long term.

First of all: The T-Rex Ultra surprised us positively during sports training. This is mainly due to the optical pulse sensor, which, compared to many other smart sports watches, copes surprisingly well with fluctuating heart rates, such as those found in HIIT or weight training. Although the T-Rex Ultra cannot quite keep up with a chest strap in terms of heart rate measurement accuracy, those who can live with small deviations are guaranteed to be happy with the Amazfit watch.

The T-Rex Ultra can also score with other good training features. Like other Amazfit devices, the smartwatch supports more than 100 different sports with their own profiles. There is also automatic recognition for running, walking, cycling, rowing, stepping and swimming as well as 25 different weight training exercises. This also worked very well in our test, although we were not able to try all of the sports mentioned. However, running and cycling were reliably detected. The recognition of the strength training exercises also worked surprisingly well, even if not all repetitions were counted correctly. Practical: after training, we can look at an evaluation in the Zepp app and see at a glance which muscles have been used. This allows individual training planning directly in the app.

Similar to activity tracking, the T-Rex Ultra has a feature that calculates the stress on the body after a sports session. The watch uses individual data such as our heart rate and body measurements to output our maximum oxygen uptake and our recovery time. The algorithm also displays the training load and the training effect of aerobic and anaerobic load. Apart from small deviations, the results matched the data of our control device (Garmin Fenix ​​6).

There were only two negative things we noticed in the test during training. As mentioned, the T-Rex Ultra has a rather bulky housing. This means that the watch can feel uncomfortable during certain exercises, for example when it presses against the back of the hand during push-ups. The watch calculates the calories burned during a sports session very conservatively: Compared to our control device (Garmin Fenix ​​6), the T-Rex Ultra reported a whole 128 kcal less in a one-hour sports session (CrossFit).

When it comes to sleep tracking, the T-Rex Ultra offers the current market standard: the watch records the individual sleep phases, our heart rate and our breathing during the night. We then get the results clearly prepared in the app. Based on the data, we can then draw long-term conclusions about our sleep hygiene. The results are only of limited significance, but as with other smartwatches, they can help to identify potential sleep disorders.

The T-Rex Ultra also offers solid standard fare when it comes to additional features. We can display notifications and specify which apps we want to receive notifications from. We can also read incoming text messages and events saved in the calendar on the display. There is also a music control that we can access at any time and with which we can operate the music played on the smartphone. However, the T-Rex Ultra does not have its own music storage and there is no way to answer messages directly on the watch display.

Amazfit specifies the battery life of the T-Rex Ultra as up to 20 days with average use. In this case, this means: The watch is worn 24 hours a day, with heart rate measurement activated and blood oxygen saturation measured twice a day. Users receive 150 messages a day, raise their wrist 30 times and exercise 90 minutes a week.

We used the T-Rex Ultra similar to this scenario, but completed significantly more training sessions (5x 60-90 minutes per week). The battery lasted 15 days – a very solid value, which is absolutely fine considering the price of the T-Rex Ultra.

Amazfit offers the T-Rex Ultra for 470 Euro at. This makes the T-Rex Ultra significantly cheaper than comparable outdoor smartwatches from Garmin and Polar, but more than twice as expensive as the Amazfit T-Rex 2 (test report). In our opinion, the price-performance ratio is still excellent, which is particularly due to the integrated GPS tracking, the map function and the robust workmanship of the watch.

The T-Rex Ultra surprised us more than once in the test. It offers what the competition from Garmin, Polar and Co. like to advertise full-bodiedly – and for a significantly lower price. For amateur athletes who spend a lot of time outdoors in nature and for whom a Garmin Fenix ​​7 (test report), Enduro 2 (test report) or Polar Grit X (test report) is too expensive, we can recommend the T-Rex Ultra without reservation. For everyone else, if you are not put off by the clumsy look of the smartwatch, you will get a real power pack with an impressive price-performance ratio.