https://techcrunch.com/2017/12/11/apple-gymkit-is-coming-to-a-treadmill-near-you/

Exercise gadget integration hasn’t exactly been elegant in the past. It’s been half a decade since Apple transitioned to the lighting connector, and still I regularly see the long-retired iPod 30-pin cable flopping off treadmill dashboards at gyms all around the country. It’s impossible to say how any of this will look five years from now, but at the very least, Apple’s new GymKit offering is certainly more refined than most of what’s come before it.

Unveiled at WWDC over the summer, the platform is designed to make wearing an Apple Watch a more seamless experience. It uses a combination of NFC and Bluetooth to maintain a constant exchange of information between the two devices. The watch is better at collecting some data (calories, heart rate) and the equipment is better at others (distance, incline). All of that data is displayed on the watch and the machine’s display in real time, and aggregated in Apple’s Health app.