Apple Watch Series 12 and Ultra 4 introduce a redesigned health sensing system that records background heart rate every five seconds throughout the day, including while users are moving.
Apple says that is 60 times more frequent than before, alongside heart rate variability readings as often as every five minutes, a 24-fold increase.
The hardware changes cover three parts of the sensor array against the wrist. A larger electrode surface fits within the same footprint to improve skin contact during ECG readings, while redesigned photodiodes sit in a ring to capture light more efficiently. Larger, more power-efficient green LEDs are designed to support accurate heart rate measurements throughout the day, including during movement.
The system builds on sensors used to track heart rate and rhythm, sleep and advanced workout metrics. More frequent readings provide additional data for health insights, including heart rate variability, or HRV, which reflects how the body responds to stress and recovery. Apple described higher variability as generally associated with better recovery.
To assess accuracy, Apple says it conducted a head-to-head study against other wearables, using an ECG chest strap as the reference. Hundreds of participants took part in running, cycling and high-intensity interval training workouts. Based on those results, the company claims Apple Watch has the most accurate heart rate sensing of any wearable.
The new sensing hardware is shared by Series 12 and Ultra 4. Apple says it will also enable new experiences on both watches, with further details still to come. Stay tuned as new health features are coming as described in the keynote…and don’t forget pricing as well.
Want to see more of our stories on Google?
P.S. Want to keep this site truly independent? Support us by buying us a beer, treating us to a coffee, or shopping through Amazon here. Links in this post are affiliate links, so we earn a tiny commission at no charge to you. Thanks for supporting independent Canadian media!
