I wore four smartwatches through a Spartan race, 12 miles of running, and sleep tracking to find the ultimate fitness companion. The Amazfit T-Rex 3 Pro consistently delivered the most accurate data, while the Galaxy Watch Ultra 2 had notable lapses in heart rate and cadence tracking.\n\nDuring sleep tracking, the Amazfit T-Rex 3 Pro gave a sleep score of 54 that matched how I felt, while the Galaxy Watch Ultra 2 reported 72. The Honor Watch 6 showed the least data, and the One Plus Watch 3 missed SpO2 and breathing quality.\n\nFor GPS accuracy during a 2.5-mile run, the Galaxy Watch Ultra 2 and Amazfit T-Rex 3 Pro tied for first, while the One Plus Watch 3 was the least accurate.

In the 5K Spartan race, the Amazfit watch properly measured waiting times at obstacles, whereas the Galaxy Watch Ultra 2 failed to record those pauses.\n\nOverall, the Amazfit T-Rex 3 Pro proved to be the most reliable and feature-rich, with the Zepp app offering excellent UI and AI-powered insights. It remains my top workout companion.