watchOS 27 Improves Apple Watch Treadmill Distance Tracking, but Results Still Vary

Apple says watchOS 27 improves distance tracking for treadmill walks and runs by refining the motion-tracking algorithms used to estimate distance from the wrist. TechRadar writer Michael Sawh tested the feature across four watches: Apple Watch Ultra 3, Apple Watch Series 11, Apple Watch Ultra 4 and Apple Watch Series 12.

Sawh compared the watches with treadmill distance readings and a Coros Pod 2 worn on his foot. His tests included one-mile runs, steady hour-long runs and interval sessions. He calibrated each watch with an outdoor run of at least 20 minutes, as Apple recommends, and kept the incline consistent. He used gym treadmills, though not always the same one, and noted that treadmill condition and belt wear could affect accuracy.

In early tests with watchOS 27 beta on Apple Watch Ultra 3 and Apple Watch Series 11, distances differed by about 300 metres from the treadmill and Coros Pod 2 readings. In tests with the public release on Apple Watch Ultra 4 and Apple Watch Series 12, the difference was roughly 200 metres. The watches were closer on steady or easier runs, but did not match the treadmill exactly. Sawh also found that the watches sometimes struggled to register faster sections, especially during intervals, and that pace readings could feel off.

He concluded that the update brought improved, but not exact, indoor distance tracking. He noted that GPS-based outdoor running remained the best way to capture distance and pace accurately.