Apple expands its GymKit feature to the iPhone and AirPods Pro 3 with iOS 27, allowing users to log treadmill workouts without an Apple Watch. The original GymKit, launched in 2017, let the Apple Watch tap gym equipment to share heart‑rate data while receiving distance, incline, pace, and calories from the machine.

With the new version, users pair their iPhone to a compatible treadmill, choose a workout mode, and start the session. The AirPods Pro 3 send real‑time heart‑rate data to the treadmill, which in turn streams precise metrics—distance, pace, incline, and calories—directly to the iPhone’s Fitness app. This eliminates the need for metal heart‑rate contacts or a separate Bluetooth strap and turns the iPhone into a full workout computer.

The feature shines as a reliable backup when an Apple Watch is dead, charging, or left at home. Workouts recorded on the iPhone sync to the Apple Watch afterward, keeping the Exercise ring accurate. While the watch still offers slightly sharper treadmill tracking in iOS 27, GymKit remains the gold standard for accuracy.

Apple’s move underscores its strategy to embed fitness into the broader ecosystem, giving iPhone users a watch‑like experience and potentially drawing new customers toward its wearable lineup.