For the better part of a year, rumors have circulated about Apple's ambitious AI-powered health coaching service, internally code-named Project Mulberry. Initially expected to debut with a redesigned Health app in iOS 26.4, the feature was first pushed back to iOS 27. Now, new reports indicate that Project Mulberry may not launch with the initial release of iOS 27, potentially arriving later in the cycle, such as with iOS 27.1 in October or even iOS 27.4 next spring.
Improved Heart-Rate Tracking in watchOS 27
While the AI health coach faces delays, Apple is reportedly making significant strides in improving heart-rate tracking on the Apple Watch with watchOS 27. According to Bloomberg's Mark Gurman, the upcoming watchOS 27 update will largely focus on stability, performance, and smaller refinements rather than introducing major new capabilities. However, improvements to heart-rate tracking are explicitly mentioned as part of the update.
Details on the specific improvements remain scarce, but users and analysts have long noted that the Apple Watch's heart-rate tracking, while generally reliable, can be inconsistent in refresh rate compared to dedicated fitness trackers like WHOOP. WHOOP's continuous, high-frequency sampling provides more granular insights, particularly for detecting heart rate variability and recovery metrics. Apple could address this by increasing the sampling frequency or improving the algorithms that filter motion artifacts.
The heart-rate tracking enhancements may also tie into Apple's broader health ecosystem, potentially preparing the hardware and software for the eventual launch of the AI health coach. Better baseline data collection could enable more personalized coaching and insights, making the AI service more effective once it arrives.
Project Mulberry Delays and Scaling Back
Project Mulberry was first reported around mid-2025. The concept involves an AI agent that provides health insights based on Apple Health data, with additional capabilities such as analyzing camera feeds to offer workout form pointers. The service was envisioned as a subscription offering, possibly under the Apple Health+ branding, competing with other health coaching platforms.
However, in February 2026, reports surfaced that Apple had scaled back its efforts on Project Mulberry. The company reportedly felt that its initial implementation was not competitive enough against existing health subscriptions on the market. Taking more time to refine the product, Apple delayed the launch from iOS 26.4 to iOS 27. Now, it appears that even that timeline is optimistic.
Mark Gurman noted in a recent Power On newsletter that he does not expect features from Project Mulberry to launch until later in the iOS 27 update cycle. This could mean a debut alongside the redesigned Health app in the fall of 2026, but the AI coaching features themselves may arrive in a subsequent update. The decision to delay was also influenced by leadership changes within Apple's health group, with executive Cue taking over and potentially reassessing priorities.
The redesigned Health app, however, is still expected to launch with iOS 27, providing a new interface and perhaps foundational features that will later support the AI coach. This staggered rollout mirrors Apple's approach with other major features, such as Apple Intelligence, which was introduced gradually across multiple iOS 18 updates.
Potential Implications for Apple Watch Users
For current Apple Watch users, the watchOS 27 heart-rate improvements could be a welcome upgrade, especially for those who rely on their watch for fitness and health tracking. More accurate and frequent heart-rate data can improve sleep tracking, workout calorie estimates, and overall health monitoring. It may also provide better data for third-party apps that use heart rate variability for stress and recovery analysis.
Looking ahead, the combination of enhanced heart-rate tracking and an AI health coach could position the Apple Watch as a more comprehensive health companion. However, the delays suggest Apple is being cautious about entering the AI health coaching space, ensuring that its offering is truly differentiated and valuable before rolling it out to millions of users.
In the meantime, Apple continues to refine its existing health features. The company has steadily added capabilities like cycle tracking, blood oxygen monitoring (where available), and the Vitals app in watchOS 11. Each iteration builds on the previous, creating a robust platform that increasingly supports proactive health management.
Source: 9to5Mac News