I wore 4 top smartwatches through a Spartan race, 12 miles of running, and sleep tracking to find the ultimate fitness companion

['Nicholas Sutrich', 'Senior Content Producer', 'Smartphones', 'Layer Van-Ds .Vds-Author Font-Size Var --Text-Base', 'Font-Size Var --Vds-Author-Font-Size', 'Var --Text-Base', 'Line-Height Var --Text-Base--Line-Height', 'Line-Height Var --Vds-Author-Line-Height', 'Var --Text-Base--Line-Height', 'Letter-Spacing Var --Tracking-Normal'] Latest from Android Central 2026-08-07 22:33:01

Most smartwatches collect the same sleep data, but every so often you'll find a watch that does something different. The Galaxy Watch Ultra 2, for example, included a skin temperature measurement, measured against a baseline it had determined in the past 2 weeks since I started wearing it. Overall, I felt like the Amazfit T-Rex 3 Pro's data was the most accurate. The Honor Watch 6, for example, got the altitude all wrong, while the Galaxy Watch Ultra 2 completely fumbled the cadence measurement. In the heart rate data, you'll see three points where the Galaxy Watch Ultra 2 did something weird.