GymKit has been one of the Apple Watch's most intelligent fitness features since its launch in 2017. It allows users to tap their watch to compatible gym equipment, sharing heart rate data while the machine returns metrics like distance, incline, pace, and calories. This seamless integration has made GymKit a gold standard for accurate workout tracking. However, with iOS 27, Apple is expanding this capability beyond the Apple Watch, enabling iPhone and AirPods Pro 3 users to experience a similar workout tracking experience without needing a watch on their wrist.

In this article, we explore the new GymKit functionality introduced in iOS 27. We tested it with a GymKit-compatible treadmill, using an iPhone paired with AirPods Pro 3. The setup is straightforward: simply tap your iPhone to the NFC reader on the equipment, choose your workout type (e.g., Indoor Walk or Indoor Run), and start moving. The treadmill then receives heart rate data from the AirPods Pro 3, which are equipped with sensors to monitor your pulse. Simultaneously, the Fitness app on the iPhone captures machine-provided metrics such as distance, pace, incline, and calorie burn. All data is stored privately on the iPhone and removed from the equipment after the session.

The Evolution of GymKit

GymKit was originally designed to bridge the gap between Apple Watch and commercial fitness machines. By using NFC to establish a connection, it eliminated the need for manual data entry or reliance on the machine's heart rate sensors. Over the years, Apple has refined the algorithm to improve accuracy, and watchOS 27 brought even better treadmill tracking. However, the core idea remains the same: precise, real-time data exchange that makes workouts more efficient and motivating.

With iOS 27, Apple is decoupling GymKit from the Apple Watch. This is a significant shift. For the first time, users who own an iPhone but not an Apple Watch can access the same high-quality data from gym equipment. This democratization of fitness tracking aligns with Apple's broader strategy to make health and fitness features available across its ecosystem, starting with the iPhone and expanding to accessories like AirPods.

How It Works: iPhone and AirPods Pro 3

The process begins by tapping your iPhone to the NFC symbol on the gym equipment. After a quick connection, the Fitness app opens and presents options like Indoor Walk or Indoor Run. Once selected, the workout starts from the machine's interface. The treadmill now uses the AirPods Pro 3 as its heart rate source, which is more reliable than holding metal contacts or wearing a separate Bluetooth chest strap. Meanwhile, the iPhone receives all the machine's data and displays it in real time on the screen.

It is important to note that the AirPods Pro 3 must have heart rate permissions enabled in Settings > Your AirPods > Privacy. By default, this might be turned off to save battery, but for this feature to work, it should be active. In our testing, when the AirPods were not connected, the iPhone disconnected from the treadmill because no heart rate source was available. Similarly, if you are wearing an Apple Watch, iOS will suggest using the Watch instead, but you can choose to continue with the iPhone.

During a 16-minute treadmill walk, we recorded 0.66 miles, 65 active calories, 97 total calories, 32 feet of elevation gain, and an average heart rate of 115 BPM. These numbers matched what an Apple Watch would have logged, confirming the accuracy of the system. The Exercise ring on Apple Watch didn't update during the workout if the watch was not worn, but once it was put back on, the rings caught up and the workout appeared in the Fitness app with all the correct data.

Why This Matters for Fitness Enthusiasts

GymKit on iPhone solves a common problem: what happens when your Apple Watch is dead, left at home, or charging? In the past, you would either skip logging the workout or rely on your iPhone's limited motion sensors, which cannot measure incline or belt distance accurately. Now, with just your phone and a pair of AirPods Pro 3, you can log a treadmill workout with the same precision as if you were wearing an Apple Watch.

This feature also serves as an enticing gateway for Apple Watch adoption. Users who experience GymKit through their iPhone may be more inclined to purchase an Apple Watch later, especially when they see how seamless the data integration is. Additionally, it strengthens Apple's fitness ecosystem. The company has been gradually moving more fitness features onto the iPhone, starting with the Fitness app becoming useful without an Apple Watch and Apple Fitness+ relying heavily on the phone as an entry point. The addition of heart rate tracking in AirPods Pro 3 (a feature first tested in Powerbeats Pro 2) further completes this vision.

For those who already own an Apple Watch, GymKit on iPhone provides a reliable backup option. But it also introduces new possibilities. Imagine finishing a workout with your watch, then deciding to do a cool-down treadmill walk without re-syncing. Or traveling without your watch charger and needing to use the hotel gym. These scenarios are now covered.

Technical Considerations and Limitations

While the experience is largely positive, there are a few things to keep in mind. The AirPods Pro 3's heart rate sensor is not as continuously active as the Apple Watch's. It samples at intervals, but for steady-state cardio like walking or running on a treadmill, this is sufficient. Apple also notes that the best heart rate data is achieved when using both AirPods Pro 3 and an Apple Watch together, with the watch using the AirPods as a supplementary source if needed.

Another limitation is that the Exercise ring on Apple Watch does not update in real time if you are not wearing the watch. However, as we experienced, the data syncs later once the watch is worn again. This is a minor inconvenience but ensures that you do not double-count activity.

Finally, not all gym equipment supports GymKit. Many commercial machines in major gym chains offer NFC connectivity, but older or budget models may not. Apple provides a list of supported equipment on its website, and users should check compatibility before relying on this feature.

Expanding the Fitness Ecosystem

iOS 27's GymKit expansion is more than just a small update; it represents a fundamental shift in how Apple approaches fitness tracking. By removing the Apple Watch requirement, Apple opens up its walled garden to millions of iPhone users who may not want to invest in a smartwatch but still desire accurate gym data. This inclusivity could drive adoption of other Apple services like Fitness+, which now has a larger potential audience.

Moreover, the move aligns with the growing trend of using hearing aid-style devices (like AirPods) as health monitors. The AirPods Pro 3 already measure heart rate, and future iterations may include additional biometrics such as blood oxygen or skin temperature. Combined with an iPhone that acts as the hub, the Apple Watch could eventually become optional for most fitness needs, though it will remain the most comprehensive option.

In conclusion, the new GymKit functionality in iOS 27 is a thoughtful addition that solves a real problem. It leverages existing technology to provide a seamless workout experience, making it easier for people to stay fit and healthy. Whether you are a seasoned Apple Watch user or a newcomer to the Apple ecosystem, this feature adds value and convenience to your gym routine.

Source:9to5Mac News