Apple Watch Series 12 and Ultra 4 review: new colors and materials are fantastic, the Health Sensing System is a big upgrade, but many features are coming later

Your heart rate data is now collected more frequently and accurately, revealing impacts of daily activities previously missed.

Apple has released the Series 12 and Ultra 4 Apple Watch models, featuring new color and material options and a significant upgrade to its Health Sensing System. The new system boasts redesigned sensors for improved ECG contact, more efficient and accurate photodiode and LED arrangements, enabling heart rate measurements every five seconds, a substantial increase from the previous five-minute interval. This enhanced accuracy is claimed to outperform competing wearables across various activities. The Series 12 introduces new aluminum finishes like Dark Bronze and Light Gold, a matte black option, and a Ceramic Shield 2 front glass for aluminum models. The titanium Series 12 comes in Radiant Gold, aiming to mimic real gold, while the ceramic version returns in Pearl White and Night Blue. The updated Health Sensing System also supports more frequent heart rate variability (HRV) sampling, tracking both overall and recovery HRV, and integrates this data into a new daytime Vitals view and a readiness score.

The more granular heart rate and HRV data collected by the new Apple Watch models enables proactive health insights, moving beyond simple activity tracking to provide a more comprehensive understanding of daily stress and recovery. The integration of this data into new features like the daytime Vitals view and a readiness score offers users a distilled, actionable metric for their overall well-being. This signifies a shift towards wearables acting as more sophisticated personal health monitors, providing deeper correlations between lifestyle, physiological responses, and readiness for activity.

Apple's enhanced Health Sensing System and the resulting data granularity are poised to influence the competitive landscape of wearable health technology. Competitors will likely face pressure to match the increased accuracy and frequency of heart rate and HRV monitoring, potentially driving further innovation in sensor technology and data analysis across the industry. The focus on providing actionable insights like readiness scores also suggests a future where wearables offer more personalized health guidance, moving beyond raw data presentation to predictive and prescriptive recommendations.