GoKawiilReleased in October 2017, Apple's GymKit is an exciting idea that was never widely adopted. The premise is simple: you tap your watch to a machine in the gym to enable data syncing in both directions. The gym equipment can display what your watch is measuring, while your watch uses the machine's metrics to better calculate the quality of your workout. However, gym equipment replacement tends to be a slow process and purchasing equipment for the home is getting more expensive every year. Given the need for an Apple Watch and a compatible cardio machine, Apple's exercise API has had a lot working against it.
With iOS 27, however, Apple is bringing GymKit to iPhone. With this update, your AirPods Pro 3 will handle heart rate data, while the iPhone becomes the screen and record-keeper for workouts. The exercise machine completes the trifecta, contributing its own gathered workout information to the Fitness app.
Nothing has changed on the compatibility front. The cardio machine still needs Apple's GymKit integration, whether you're using an Apple Watch or an iPhone. iOS 27 just adds the same tap-to-connect option for iPhone, so you use the NFC reader with your phone instead of your watch.
Without GymKit integration, iPhones and AirPods are still useful for ordinary workout tracking. They just won't pull any data from the exercise equipment.