
10km Showdown: Fitbit Air vs Apple Watch Ultra 3 on heart rate and calories
On a 10km run, the author compares Google's new screenless Fitbit Air with the Apple Watch Ultra 3, using a Polar H10 chest strap as a backstop (which malfunctioned). Both devices rely on optical HR to estimate calories, but the Air piggybacks on the iPhone’s GPS (no built‑in GPS) while the Ultra 3 has built‑in GPS, so Apple is expected to be more accurate for distance metrics. Health data from Google Health and Apple Health aren’t linked in this test. The piece also touches on Fitbit’s app changes and the Air’s AI Health Coach, with the run results shown in a navigable on‑page chart detailing heart rate, calories, and pace differences.





