Apple overhauls the Health app with AI alongside watchOS 27 and new heart sensors on Series 12/Ultra 4

Apple has announced major updates to Apple Watch and the Health app, focused on more detailed cardiovascular measurement and an AI assistant. Series 12 and Ultra 4 ship with upgraded optical and electrical heart sensors, validated with over 1,000 participants, measuring heart rate every 5 seconds throughout the day, while HRV sampling increases 24x (every 5 minutes) to detect stress and recovery patterns faster.

A Readiness Score on a 0–10 scale combines activity, heart data and sleep to offer guidance ranging from "recover" to "go for it," updating continuously through the day as activity changes. The redesigned Health app (arriving with iOS 27 in late 2026) uses Apple Intelligence to make complex data easier to understand through two main tabs: Insights for daily summaries with personalized recommendations, and Longevity for long-term health assessment, including a "Health Age" score calculated against calendar age.

Additional capabilities include at-home movement assessments (flexibility, strength, balance, VO2 max) via the iPhone camera, lab test ordering (U.S. only, around $119), menopause tracking with pre-menopause alerts, and a redesigned workout coach. watchOS 27 ships September 14 for Series 9 and later and SE 3 and later, but the new sensors are exclusive to Series 12 and Ultra 4, and the full Health app experience requires an Apple Intelligence-capable device.

Source: Apple