Apple promotes health monitoring as the top feature of its latest smartwatch, Apple Watch Series 12. Although the new edition brings a typical Apple Watch experience, its most significant modifications lie below the display. A rebuilt Health Sensing System allows for blood oxygen and electrical heart-rate sensors to take readings more often, plus other new features aimed at revealing what’s happening inside users’ bodies as they go.
The biggest change is the frequency of the background heart-rate monitoring. Apple Watch Series 12 can monitor your heart rate every five seconds during the day so it is most frequent background heart-rate sensing Apple has ever done on an Apple Watch. Apple says that’s 60 times more granular than the background readings on Series 11. The system relies on larger, more energy efficient green LEDs in the optical heart sensor to take these extra measurements.
The five-minute figure for Series 12 is in fact a measurement of heart-rate variability or ‘HRV’. Apple Watch is capable of measuring this as frequently as every five minutes, which it claims to be 24 times more frequent than previous models. This can give some valuable insight on stress and recovery changes and allows the watch to build up a more detailed picture of the users state.
Apple has reengineered the optical and electrical heart sensors as part of the new Health Sensing System. The company claims a study of over 1,000 users found the Series 12’s heart-rate sensing to be the most accurate of all the wearables in the comparison. The added sampling aims to provide the watch more data to draw upon when providing fitness and wellness calculations.
Another feature that has received this extra information is Apple’s new Readiness experience. Rather than throwing a bunch of numbers at users, the watch adds experience data, recent activity, sleep, and vital measurements to generate a daily score from 0 to 10. The idea behind the rating is to give users a feel for whether they might be better prepared for rigorous activity or should take it easy.
This score is also fluid. Apple claims that the score can vary throughout the day as new information (like after hard exercise, or changes in daytime vital readings) is fed into the model. This makes the stat more than a once-per-day fitness indicator it becomes a continual indicator of how the system is reacting.
This is a major update in the Vitals experience too. Other than HRV, you now have it appearing plus other measures of health and your overnight and day views give it context. You’ve now also got recovery HRV mapped against your own personal baseline so you can better understand the significance of any deviations.
This extra heart reading further backs up Apple’s other health-specific features like the heart-rate notifications, ECG feature, sleep tracking, and other health metrics. Apple is selling the Series 12 as the next tool to help users recognize long-term trends instead of just counting steps or recording workouts.