Apple (MacRumors):

The new Health Sensing System on Apple Watch Series 12 and Apple Watch Ultra 4 features new optical and electrical heart sensors, enabling higher-frequency heart rate and heart rate variability (HRV) measurements, a new readiness score, a more comprehensive Vitals overview with the addition of HRV, and an updated Heart Rate app.

[…]

Apple Watch Series 12 and Apple Watch Ultra 4 introduce readiness — a new feature that analyzes a user’s recent activity, vitals, and sleep score, and then provides a single 0-10 score each day with a clear, actionable recommendation: Recover, Pace Yourself, Ready, or Go For It. This helps a user decide how to take on their workday or tackle their training plan.

[…]

A new Longevity tab analyzes a user’s longitudinal health data for deeper insights into heart health, sleep, mental wellbeing, movement health, metabolic health, hearing, and nutrition. The tab includes Health Age, a new feature that uses Apple Watch data to show users how their metrics are tracking relative to their chronological age, informed by the best available science.

Kuba Suder:

I wonder how much of this new health stuff will work with older / SE watches… probably not much?

Previously:

• Apple Watch Ultra 4
• Apple Watch Series 12

Apple Watch Apple Watch Series 12 Apple Watch Ultra 4 Health.app iOS iOS 27 watchOS watchOS 27