GoKawiilYou wouldn’t know that the Apple Watch Series 12 is a big deal just by looking at it. It has the same design, buttons, sizes, and sensor types as generations of Apple Watches before it. But under the hood, the Series 12 builds in major changes that lay the groundwork for big ideas about the future of health and wearables.
These ideas — and this year’s updates — can be divided into two parts: catching up to the recent boom in AI health and leading the way in AI wearables that surface helpful information based on your entire day. When it comes to the former, Apple is catching up to the rest of the wearable space, which has eagerly embraced AI as a way to make sense of all your health data. With the latter, Apple is potentially kicking the door down on what’s been a niche, nascent, and recently problematic market. (Either way you slice it, AI is part of the equation.) Most of the ideas explored with the Series 12 aren’t novel, but they haven’t been implemented by a company with Apple’s scale or reputation.
After a week with the Series 12, I can’t say I have a complete picture. Several of the most interesting health and AI features aren’t launching until later this year and weren’t available for review. But even without them, the revamped internals provide some meaningful upgrades. So for now, this is a look at the health features that’ll be available at launch — and a preview of the wild AI ideas to come.
New hardware
Two key hardware updates separate the Series 12 (and the Ultra 4) from previous Apple Watches. The first is the new S11 chip, which features a secure exclave for microphone data processing on top of a faster CPU, GPU, and Neural Engine. There’s also a completely redesigned health sensor array. This new array doesn’t necessarily capture new data, but it enables the watch to measure health metrics in a more frequent, accurate, and power-efficient way. The electrodes that enable the EKG feature are larger to ensure better skin contact, the photodiodes have been reconfigured to capture reflected light more efficiently, and larger, less power-hungry optical LEDs are in place to shine light into the skin.
This is a significant hardware redesign compared to previous Apple Watches.
Together, these hardware upgrades enable a host of new software features, including more frequent heart rate sampling, a new readiness score, and a brave new world of Audio Intelligence, which is what Apple is calling its upcoming suite of AI-powered ambient listening features.
Most notably, the redesigned sensors mean the Series 12 and Ultra 4 are now capable of truly continuous heart rate monitoring. Previously, to preserve charge, Apple Watches only sampled heart rate once every five minutes when you weren’t working out. Now, the Series 12 measures heart rate every five seconds, both at rest and during activities. Other wearable companies have been able to do this for ages, but this is a genuinely helpful update for folks who might need to monitor heart rate due to chronic illnesses.
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Apple put out a white paper comparing how accurate its continuous heart rate monitoring is to a gold-standard Polar H10 chest strap, as well as competitors like the Pixel Watch 4, Samsung Galaxy Watch 8, Oura Ring 5, and Whoop across several types of workouts and at rest. (It’s an interesting read for wearable nerds!) I’d need roughly eight arms and legs to replicate this study in a week, and alas, I’m not an octopus. However, I did wear an H10 chest strap during two runs (one steady state and one interval run), a walk, and while at rest. At all times, the Series 12 was within five beats per minute of the H10. There was a slight lag compared to the H10, but in regular use, you’re not going to notice that four-second difference.
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