Apple Watch Series 12, Ultra 4 have wearables' “most accurate heart rate sensing"

New Apple Intelligence features, too.
https://arstechnica.com/gadgets/2026/09/apple-watch-series-12-ultra-4-have-wearables-most-accurate-heart-rate-sensing/?utm_brand=arstechnica&utm_social-type=owned&utm_source=mastodon&utm_medium=social