Apple watchOS 4, with better heart rate monitoring, arrives September 19

The updated software powering the Apple Watch, watchOS 4, will be released on September 19, 2017, for all Watch customers, according to Apple COO Jeff Williams, speaking at Apple’s iPhone press conference today. The updated software, which includes features like new watchfaces, improved fitness coaching, a redesigned music experience and more, was previously announced this summer at WWDC.

Some of the biggest changes in the new watchOS have to do with its health-related features, for obvious reasons. Apple vaguely referred to the Apple Watch as the “most used heart rate monitor,” but didn’t offer a source for that data, for example. But Apple Watch, like most wearables today, attract many users because of their health monitoring and fitness features.

One notable change with watchOS 4 is the introduction of a new mode called  “Gym Connect,” which allows you to sync directly with gym equipment like treadmills and ellipticals.

It will also include new heart rate sampling, which provides a better resting heart rate measurement. That is, Apple Watch will now notify you if you have an elevated heart rate but don’t appear to be active, or when you reach a certain level during a workout. You’ll be able to see both your resting heart rate and recovery heart rate in the app, too.

The “Apple Heart Study,” another Apple partnership with the medical community, was also announced. This will utilize data from Apple Watch to monitor for arrhythmia. People will be able to participate in the study with Stanford by downloading an app from the App Store, Williams said.

The updated software for Apple Watch is arriving alongside the next-gen hardware, Apple Watch 3.