Apple's New $399 Watch Checks Your Heart Every 5 Seconds
It watches your heart all day and tells you when to rest.
Apple unveiled the Apple Watch Series 12, a $399 smartwatch, at its Sept. 9 event — and it's built to collect more health information while you go about your day. It measures your heart rate every five seconds throughout the day, with HRV measured as often as every five minutes. A new Readiness score from 0 to 10 draws on recent activity, training load, sleep, and vitals, with recommendations ranging from Recover to Go For It. And Live Rewind can bring the previous 15 seconds of a conversation back as text on your wrist when you miss a name or a few words. As for charging, Apple says 15 minutes on the charger can provide up to 12 hours of use.
- Your heart rate is checked every 5 seconds, and a daily Readiness score from 0 to 10 tells you whether to train hard or rest.
- Live Rewind replays the last 15 seconds of a conversation as text on your wrist — but it needs an iPhone 16 or newer and isn't available in the EU yet.
- It costs $399, and a quick 15-minute charge now gives you roughly 12 hours of battery.
Why It Matters
A watch that monitors your heart all day could flag health problems early and stop you from burning out.