Apple Watch Series 12 and Ultra 4 introduce advanced health tracking

Apple has launched the Apple Watch Series 12 and Apple Watch Ultra 4, focusing on significant internal hardware upgrades rather than design changes. Both models feature an overhauled Health Sensing System powered by the S11 chip, which enables much more frequent heart rate measurements—occurring every five seconds compared to the previous five-minute intervals.

A central new feature is the Readiness Score, a daily metric that assesses physical recovery and readiness for activity. This score is calculated using a baseline established over several days of sleep and vital data, incorporating metrics such as heart rate variability (HRV), respiratory rate, blood oxygen, and training load.

The Series 12 is designed as a lighter, more discreet daily wearable, while the Ultra 4 maintains its 49-millimeter titanium chassis, offering enhanced brightness, dual-frequency GPS, and specialized outdoor and diving functions. Additionally, reports indicate Apple is exploring a separate, screenless fitness tracker in the form of a fabric band to compete in the specialized health-monitoring market.