{
  "id": 8326991,
  "title": "The Quantified Scientist tests the Apple Watch Series 12’s new heart rate sensor",
  "url": "https://urgent.news/2026/09/18/the-quantified-scientist-tests-the-apple-watch-series-12s-new-heart",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-09-18T23:08:18.000Z",
  "source": {
    "name": "9to5Mac",
    "slug": "9to5mac",
    "url": "https://9to5mac.com/2026/09/18/the-quantified-scientist-tests-the-apple-watch-series-12s-new-heart-rate-sensor/"
  },
  "original_language": "en",
  "account": "Rob ter Horst, from The Quantified Scientist YouTube channel, conducted a thorough comparison of the new heart rate sensor in the Apple Watch Series 12 and a Polar H10 ECG chest strap. He tested the sensor during indoor cycling, running, and weightlifting, and noted that the Apple Watch Series 12's sensor performed exceptionally well, particularly during indoor cycling, with nearly identical readings to the Polar H10. During running, the Series 12 also performed well, with a 0.98 correlation to the chest strap, slightly lower than the indoor cycling session. However, during weightlifting, the Series 12 showed a lower correlation of 0.97, which ter Horst still considered \"quite good\" compared to other devices he has tested. The Series 12's step counter proved accurate, matching manual counts closely. Ter Horst also observed that the new Apple Watch Series 12's heart rate accuracy was broadly similar to that of the Series 11, although Apple may still be refining its algorithms.",
  "summary": "In a new video, The Quantified Scientist’s Rob ter Horst compares the new Apple Watch Series 12’s heart rate sensor against a Polar H10 ECG chest strap. Here’s what he found. more…",
  "key_points": [
    "Apple Watch Series 12's new heart rate sensor performs well during indoor cycling.",
    "Series 12 shows high correlation (0.98) with Polar H10 during indoor cycling.",
    "Weightlifting shows slightly lower correlation (0.97) for Series 12's heart rate sensor."
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}