GymKit has been one of Apple Watch’s smartest fitness features since its introduction in 2017. Initially designed to bridge the gap between Apple Watch and compatible gym equipment, it allowed users to tap their watch to a treadmill, elliptical, or bike, sharing heart rate data while receiving machine metrics like distance, incline, pace, and calories. This seamless integration reduced the need for manual data entry and improved workout accuracy. With iOS 27, Apple is expanding that concept beyond the Apple Watch, enabling iPhone and AirPods Pro 3 to serve as a complete workout tracking system at the gym. Testing a GymKit-compatible treadmill with an iPhone and AirPods Pro 3 reveals that the experience essentially mirrors what Apple Watch users have enjoyed for years—just without wearing the watch itself. This development could prove invaluable in various scenarios, from forgotten or dead watches to encouraging new users to explore Apple’s fitness ecosystem.
GymKit, no Apple Watch required
The setup process for the new GymKit on iPhone is straightforward. A simple tap of the iPhone to the treadmill’s NFC reader initiates the connection. The user is then prompted to select a workout type—Indoor Walk or Indoor Run—and the workout begins from the treadmill console. Just like with Apple Watch, workout data is stored privately on the iPhone and is automatically removed from the equipment after the session ends. This ensures privacy and prevents data clutter on public machines. Once the workout starts, the treadmill receives heart-rate data from the AirPods Pro 3, which are equipped with optical sensors capable of measuring heart rate. At the same time, the Fitness app on iPhone receives the treadmill’s real-time metrics, including distance, pace, incline, and calorie burn. Treadmills have inherent advantages over wrist-based tracking: they know exact belt speed, incline settings, and can calculate distance more precisely than an iPhone or even an Apple Watch. While watchOS 27 has improved Apple Watch treadmill tracking accuracy, GymKit remains the gold standard because it directly ingests machine data.
GymKit also eliminates two common gym annoyances. Users no longer need to grip the metal heart-rate sensors on the treadmill handles—a notoriously unreliable and uncomfortable method. Additionally, there is no need to wear a separate Bluetooth heart-rate strap, which many gym-goers find cumbersome. The AirPods Pro 3 double as both a heart-rate monitor and an audio source for music or podcasts, while the iPhone serves as the workout computer, displaying metrics and logging the session. This integration turns the trio—iPhone, AirPods Pro 3, and treadmill—into a cohesive fitness tracking system that rivals Apple Watch in data accuracy.
iPhone and AirPods have become more like an Apple Watch
Apple has been steadily shifting more fitness features onto the iPhone over the past several years. The Fitness app originally required an Apple Watch to function, but with the introduction of Apple Fitness+ and later updates, iPhone users could track basic movement and workout data without the accessory. The Fitness app now offers a full suite of activity tracking, including steps, walking distance, and even some workout types using the iPhone’s motion sensors. The AirPods Pro 3 represent a major milestone as the first AirPods model to include heart-rate monitoring, following a test run with Powerbeats Pro 2. This addition allowed Apple to offload heart-rate sensing from the watch to the earbuds, opening up new possibilities for iPhone-centric fitness tracking. iOS 27 brings all these pieces together in a cohesive way. The GymKit on iPhone feature is not intended to replace Apple Watch for daily wearers; rather, it serves as a convenient backup option when the watch is dead, charging, or inadvertently left at home. For users who do not own an Apple Watch, it offers a taste of the Apple Watch workout experience, potentially enticing them to become future customers.
During testing with iOS 27 beta 1, the Exercise ring on Apple Watch did not update while working out without the watch. However, once the user put the watch back on, the Exercise ring caught up, and the workout appeared in the Fitness app with all the correct data. This suggests that the system syncs seamlessly when the watch is reconnected, maintaining data continuity. A sample 16-minute treadmill walk recorded 0.66 miles, 65 active calories, 97 total calories, 32 feet of elevation gain, and a 115 BPM average heart rate—identical to what would have been logged if an Apple Watch had been worn. If the user attempted to use GymKit on iPhone without AirPods, the connection dropped when the workout started because there was no heart-rate source. If the user tried to start GymKit from iPhone while wearing an Apple Watch, iOS redirected them to the Workout app on the watch, though it still allowed proceeding without the watch. AirPods heart-rate permission must be enabled in Settings under the AirPods privacy options; a theoretical battery-saving toggle was tested and later turned back on after this feature proved its worth. The AirPods Pro 3 can also work concurrently with an Apple Watch to provide the best available heart-rate data.
GymKit on iPhone with AirPods is a great addition to Apple’s Fitness ecosystem
GymKit on iPhone may seem like a minor feature until it solves a real-world problem. For dedicated Apple Watch users, the device remains the default workout tracker due to its always-on convenience and health sensors. But when the watch is unavailable—perhaps due to forgetting it at home, a dead battery, or being away for travel—the iPhone and AirPods Pro 3 combination now offers a reliable alternative. The ability to log a treadmill workout with genuine heart-rate data and accurate machine metrics is a significant upgrade over relying solely on iPhone motion sensors, which cannot detect incline or precise belt distance. This feature reinforces Apple’s broader fitness strategy by making health tracking more flexible and accessible. It also lowers the barrier for users who may be considering an Apple Watch, allowing them to experience the ecosystem’s core benefits through devices they already own. By expanding GymKit to iPhone and AirPods, Apple has created a more complete fitness ecosystem that adapts to various user needs and lifestyles.
The integration also highlights Apple’s commitment to maintaining data privacy. Workout information is stored on the user’s device and automatically removed from shared equipment, preventing any data persistence on public machines. This is especially important for gym environments where multiple people use the same equipment throughout the day. The seamless sync with the Fitness app and Apple Watch rings ensures that users do not miss any health metrics even if they switch devices mid-day. As more fitness equipment becomes GymKit-compatible, this feature could become a standard expectation for iPhone users who frequent gyms. While the current implementation focuses on treadmills, it is likely that other GymKit-enabled machines such as ellipticals, bikes, and stair climbers will also work with iPhone and AirPods Pro 3 in future updates. The success of this feature could drive further adoption of GymKit technology across the fitness industry, benefiting both Apple and gym equipment manufacturers.
Overall, GymKit on iPhone with AirPods represents a thoughtful expansion of Apple’s fitness capabilities. It addresses common pain points, enhances accuracy, and provides a valuable fallback option. Users who have been relying on their Apple Watch for gym workouts can now have peace of mind knowing that their iPhone and AirPods Pro 3 can fill the gap. This update also signals Apple’s intent to make health and fitness features more ubiquitous across its product lineup, encouraging users to stay active with minimal reliance on a single device. The next time you head to the gym and realize your Apple Watch is still on the nightstand, your iPhone and AirPods Pro 3—with iOS 27—are ready to step in and deliver a near-Apple Watch experience.
Source:9to5Mac News