The striking Amazfit T-Rex Pro offers many settings and functions at a good price

At first glance, the T-Rex Pro looks bulky, which is also suggested by the name. That's why you're surprised at how light it is when you pick it up. At 46 g (~1.6 oz, without strap), it weighs less than the Huawei Watch GT 2 Pro (52 g/~1.8 oz) with roughly the same case diameter. Admittedly, Huawei also used metal in the latter. Amazfit was thrifty and only coated the polycarbonate casing's bezel with a hint of metal via a spraying process.

However, the metallic look suits the smartwatch well, which has passed 15 endurance tests according to military standard MIL-STD-810G. In detail, the shock-resistant watch can withstand temperatures between -40 and +70 degrees Celsius (~ -40 and +158 degrees Fahrenheit) as well as ice and freezing rain. It must also be able to survive situations in which it is exposed to moisture for up to 240 hours or salt spray for up to 96 hours. In addition, the case is water resistant up to 10 ATM.

For the band, Amazfit has opted for silicone rather than the more robust Flurelastomer material. Grooves on the inside as well as many recesses for the buckle's spine are supposed to minimize the sweat that develops under the band during an active workout. In practice, hardly any moisture actually collected there during sports. However, the connection of the 22 mm (~0.87 in) wide strap is atypical, and there is also no quick-release buckle, which many watches now have.

The AMOLED regulates its brightness with the help of a sensor and was easy to read outdoors in the test. When navigating, the T-Rex Pro connects to GPS and one of the three satellite systems Galileo, GLONASS or Beidou.

Other sensors include a geomagnetic sensor, accelerometer, gyroscope, barometer, and a PPG sensor for measuring heart rate and oxygen saturation. NFC, speakers or a microphone are not on board.

The display is activated when the arm is lifted or one of the four side buttons is pressed, but not by tapping the display. Some operating steps can be accessed via gesture as well as via a key. For example, a vertical gesture downwards opens the access menu and also the upper left button. In contrast, only a vertical gesture to the right opens the notifications on the screen. The training app is assigned to the upper right button by default, but you can personalize it. The lower right button or a swipe gesture to the left opens the app overview. The lower left button or a vertical gesture upwards opens the widget list.

Widgets do not fill the entire screen on the smartwatch like on most smartwatches, but form a list that can be scrolled through with the two left buttons. Tapping on a widget or selecting it with the upper right button opens the corresponding app.

The smartwatch measures the heart rate and the body's stress response around the clock if desired. The intervals between the heart rate measurements range from 1 to 30 minutes, depending on the setting. Falling below or exceeding previously set pulse limits triggers a warning.

The T-Rex Pro only measures oxygen saturation manually, and not automatically at night. According to the manufacturer, the tracker detects when the user is exposed to major changes in altitude and then reminds them to check their oxygen saturation. We were not able to verify this in the test.

In addition, like other fitness trackers, the T-Rex Pro also counts the number of steps taken and determines the distance and calorie burn from that. The dashboard on the smartphone brings all analyses together.

Compared to its predecessor, the Amazfit T-Rex presented at CES 2020, the successor offers some added value in the area of workout and training. These include, as mentioned earlier, barometric sensor for altitude profiles, tracking via 4 instead of 2 satellite navigation systems, and an increase in water resistance to 10 instead of 5 ATM.

The T-Rex pro makes a leap especially in the supported workouts, which now include over 100 compared to only 14 on the predecessor

You can activate automatic recognition individually for outdoor running, treadmill, walking, indoor walking, outdoor cycling, cross training, rowing machine and pool swimming. In addition, the sensitivity with which the smartwatch reacts to the activity of its wearer can be set, and whether it automatically records the detected workout or only after feedback from the user. In this way, Huami/Zepp combines the approach of Huawei, whose wearables initially only output a message that has to be acknowledged, and Fitbit, which automatically starts recording upon recognition.

When running, a "Virtual Rabbit" can take over the role of a virtual training partner whose speed you want to beat. If you specify a target stride rate, the fitness tracker vibrates in a matching beat pattern.

For many sports, the data display can be adjusted via the app and a 3D mode can be activated for trail running, which combines the 2D distance with the altitude changes. The calculation of the maximum oxygen uptake VO2max (only when running outdoors) and the training analysis are based on the Firstbeat algorithms.

Not tested, but according to the manufacturer, on board are the detection of swimming style, training length and frequency as well as SWOLF determination during swimming.

Amazfit delivers the T-Rex Pro in Meteorite Black, Desert Grey, and Steel Blue, and the price has barely dropped below the MSRP of 169 Euros (~$202) at the moment. You can get it from online retailers like Amazon or directly from the manufacturer.