watchOS 27: Improved heart rate – Health Coach delayed Apfelpatient

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Apple isn't preparing a major wave of new features for watchOS 27, but is focusing on stability, refinements, and a specific hardware-related improvement: Heart rate measurement on the Apple Watch is expected to become more precise. The highly anticipated AI health coach "Project Mulberry," however, is likely to launch later in the iOS 27 cycle.

While iOS 27 delivers a packed feature set with a Siri redesign, new image generation, and the opening of streaming capabilities, the concurrently released watchOS 27 update is noticeably more restrained. A new Bloomberg report outlines the direction: The WWDC 2026 generation primarily brings stability and a concrete sensor improvement to the Apple Watch – while the originally ambitious Health Coach project is being further delayed.

watchOS 27 focuses on substance over spectacle

The focus of the new Apple Watch software is on stability, performance, and minor refinements. According to the report, no major new features are planned. This is an unusual approach for a major Apple operating system release, but it suggests a deliberate decision: Instead of a broad wave of features, watchOS 27 will receive a maintenance update with targeted improvements.

A piece of hardware logic is taking center stage: the Apple Watch's heart rate measurement is expected to be noticeably improved. The report doesn't provide details on the specific implementation. Whether the improvement will be achieved through a higher sampling rate, different sensor logic, or new evaluation algorithms remains unclear.

Why heart rate accuracy matters

The Apple Watch has gained many health features in recent generations – from blood oxygen monitoring and sleep tracking to workout analysis. All of these rely on heart rate measurement as their fundamental signal. When comparing the Apple Watch to specialized fitness trackers like WHOOP or Oura, one key difference becomes apparent: the consistency with which the data is updated over extended periods.

More accurate heart rate measurement would not only be noticeable in the workout display, but would also improve all subsequent functions – including sleep and recovery analyses, as well as alerts for abnormalities. This update thus aligns well with a planned Apple project, which, however, has been further delayed.

Project Mulberry: Delay instead of premiere

The AI health coach, internally known as Project Mulberry, was originally slated to launch alongside a revamped Health app in iOS 26.4. However, the project was scaled back in early 2026 because Apple internally deemed the offering uncompetitive compared to other health subscription services. Since then, development has continued under new leadership: Eddy Cue has taken over the Apple Health group.

Mulberry is still planning to support iOS 27, but a first-time release this fall is now considered unlikely. The Power On newsletter places the launch "later in the iOS 27 release cycle." This could mean iOS 27.1 in October, iOS 27.4 in spring 2027, or a point update in between.

What Mulberry is supposed to do

Mulberry is designed as an AI agent that derives insights from Apple Health data and provides individually tailored advice. A camera function is also planned: users will be able to share their live camera feed with the agent, which will then provide corrective feedback during a workout – for example, regarding posture or movement sequence. The coach is linked to a paid Apple Health+ subscription, which Apple intends to position as a long-term extension of its services division.

The fact that the project is being postponed again has a clear reason: Apple doesn't want to launch a half-baked offering in a market already saturated with providers like WHOOP, Oura, Google Fitbit, and numerous app-based coaches. The risk of entering an already crowded category with a weak AI coach apparently outweighs the pressure of a timely release.

Health app redesign could still start

Even though the AI coach will arrive later, the redesigned Health app interface should be available at the iOS 27 launch. The report explicitly separates the two components: The redesign could be included with iOS 27, while the coach features will follow in later point updates. This means users will initially receive a more modern Health interface, which will later be enhanced with AI-powered features.

Two movements, one image

Improved heart rate measurement in watchOS 27 on the one hand, a delayed AI coach on the other – together, these paint a consistent picture of Apple's health strategy for 2026. The hardware foundations are being expanded before the ambitious software product follows. It's a more cautious approach than Apple usually takes in the AI arena – fitting for an Apple Watch lineup that is already heading towards rather small steps this year. How Apple will present the interplay of sensors, data, and AI at WWDC 2026 should become clearer on June 8th. (Image: Shutterstock / BadPixma)