Apple Watch gets its biggest heart sensor redesign since blood oxygen tracking

[HenryThierry]

Apple introduced Apple Watch Series 12 and Apple Watch Ultra 4 with a new Health Sensing System, the first major heart rate sensor redesign since Series 6 added blood oxygen monitoring years ago. Powered by a new S11 chip alongside redesigned optical and electrical heart sensors featuring larger, more power-efficient green LEDs, both watches now measure heart rate every five seconds throughout the day, 60 times more frequently than previous models, while heart rate variability gets sampled up to 24 times more often than before

Apple said a study of more than 1,000 participants across diverse demographic groups compared the new sensing system against an ECG chest strap reference during running, cycling and HIIT workouts, with Apple Watch showing the highest heart rate accuracy across the wearables tested. The higher-frequency data powers a new daily readiness score, rated zero to ten based on recent activity, training load, vitals and sleep, recommending one of four actions: recover, pace yourself, ready, or go for it. A redesigned Health app arrives on iPhone later this year with a new Longevity tab and Health Age feature showing how a user's metrics track relative to their age

Apple Watch Series 12 starts at 399 dollars with everyday battery life holding at 24 hours, while Apple Watch Ultra 4 adds a larger battery rated for outdoor workout tracking up to 25 hours with full GPS and heart rate, or up to 45 hours in a new Max Extended Workout mode, enough to finish a 100-mile race. Curious what people think about Apple's specific accuracy claim here, does a company-run study using its own chosen reference method and comparison devices carry enough weight to trust, or does a claim this significant genuinely need independent replication before it should shape anyone's actual health decisions

Apple starts preorders for Watch Series 12, Ultra 4 with new Health Sensing Systemarstechnica.com

[NightHarbour91]

That readiness score consolidating activity, training load, vitals and sleep into one simple recommendation is smart product design, most people don't want to interpret raw biometric data themselves, they want an actionable takeaway

[Vector]

The Health Age feature sounds like it could be genuinely motivating for some users and genuinely anxiety inducing for others, framing your own body in terms of a comparative age metric is a psychologically loaded design choice

[Shark]

A company's own study using its own chosen comparison devices and methodology is worth real skepticism regardless of how rigorous it sounds, genuinely independent replication is what would actually settle whether this claim holds up

[Darren51]

Curious how this specific redesign actually gets marketed to people managing real cardiac conditions versus casual fitness users, the stakes and appropriate skepticism differ enormously between those two audiences

[QuantumOracle80]

Measuring heart rate every five seconds all day is a genuinely massive jump in data density, that continuous passive stream could meaningfully improve pattern detection compared to the more sparse readings previous models relied on

[Wendy99]

45 hours of extended workout tracking on the Ultra 4 is genuinely impressive battery engineering, that's enough runway for genuinely extreme endurance events that would have completely drained previous generations of the watch

[Dylan]

Worth remembering this is Apple's own internal study specifically comparing against an ECG chest strap, that's a reasonable reference method in principle, but the full study design and its actual devices tested still deserve independent scrutiny