GoKawiil
Tech News
Apple's new Watch Series 12 and Ultra 4 use a Health Sensing System that samples heart rate every five seconds instead of every five minutes, requiring the optical sensor's green light to flash almost continuously. To avoid that light being visible in dark settings, Theater Mode automatically slows heart rate readings back to five-minute intervals, but a new setting lets users override this and keep continuous measurements.
Apple has built native live step tracking directly into the watch face on the new Watch Series 12 and Ultra 4, joining live heart rate as a standard complication option from the Fitness app. Previously, step data was only viewable inside the Fitness or Health apps, even though third-party apps like Pedometer++ had offered on-face step counts for years.
The Quantified Scientist's Rob ter Horst compared the Apple Watch Series 12's redesigned heart rate sensor against a Polar H10 chest strap across cycling, running, and weightlifting. He found near-perfect correlation during cycling, strong results while running, and solid but slightly weaker accuracy during weightlifting, an exercise notoriously difficult for wrist sensors to track.
Apple's Watch Ultra 4 introduces a revamped sensor system with five-second heart rate readings, an improved pedometer, and a new Readiness feature that combines recent activity and sleep data. Samsung's Galaxy Watch Ultra 2 counters with an expanded Vitals suite in its Health app, offering daily blood pressure estimates, a Heart Health Score, antioxidant readings, and trail-running hydration guidance. Both devices share core safety tools like Emergency SOS, fall detection, and alert sirens, though only Apple's watch adds crash detection.
Retailers are discounting the Pixel Watch 5 LTE model by roughly 20%, or about $100 off, just weeks after its launch. The smartwatch includes heart-rate tracking, over 50 workout modes, cellular connectivity, and fast charging.
Apple's marketing materials for the Apple Watch Series 12 and Ultra 4 reveal that the small circular Heart Rate complication, previously just an app-launcher icon, will now display an actual live heart rate number. This upgrade is enabled by the new Health Sensing System, which measures heart rate every five seconds—60 times more often than earlier Apple Watch models. The feature does not appear on watchOS 27's release candidate for the older Series 11 and Ultra 3, suggesting it's tied to new hardware.
Apple's new Ultra 4 keeps the same design as Ultra 3 but adds a new S11 chip, doubles RAM to 4GB, and introduces a redesigned Health Sensing System with upgraded heart rate and HRV tracking. New features include high-frequency background heart rate monitoring, a heart rate watch face complication, more frequent HRV readings, a new Recovery HRV metric, and more accurate real-time step tracking.
Apple published a detailed study comparing the heart rate sensing of its new Health Sensing System in Apple Watch Series 12 and Ultra 4 against rivals like Garmin, Google Pixel Watch, Huawei, Samsung, WHOOP, and Oura Ring. The test involved over 1,400 participants across five sites in the US and Malaysia, using a Polar H10 chest strap as the accuracy benchmark during activities like running, cycling, HIIT, and daily tasks.
Apple's new $799 Watch Ultra 4 pairs a redesigned sensor array—32 electrodes arranged like flower petals—with the new S11 chip, enabling heart-rate readings every 5 seconds and HRV checks every 5 minutes, far more frequent than prior models. That increased sampling powers a new Readiness score that updates throughout the day rather than relying mainly on overnight data, plus a Daytime toggle in the Vitals app to view daytime alongside nighttime metrics.
Apple's Series 12 smartwatch features a redesigned sensor layout with more diodes and electrodes for greater skin contact, enabling more frequent and accurate heart rate and HRV readings. This data powers a new Readiness app that generates a daily 0-10 score based on activity, sleep and vitals, alongside a redesigned Health app with Apple Intelligence summaries for compatible iPhones.
Apple unveiled the Watch Series 12 and Ultra 4, both built around a new S11 chip and a redesigned Health Sensing System aimed at improving heart rate and heart rate variability tracking. The system uses ring-arranged photodiodes, larger electrodes, and bigger, more efficient green LEDs to measure heart rate every five seconds, with HRV readings taken up to 24 times more often than before. Preorders for both models are now open.
Apple unveiled the Watch Ultra 4, its top-tier smartwatch, featuring an S11 chip, upgraded heart-rate sensors, and battery life reaching 84 hours in low-power mode or 50 hours in normal use. The device introduces a daily readiness score, a VO2 Max test, and an AI-powered insights tab in the redesigned Health app, plus audio intelligence features for environmental sound alerts and conversation tracking.