The Quantified Scientist tests the Apple Watch Series 12’s new heart rate sensor

The Apple Watch Series 12's heart rate sensor has undergone a complete revamp, allowing for more frequent measurements every five seconds, even when the user is inactive. This update is significant for users interested in understanding how daily activities impact their heart rate, providing more comprehensive data.

During testing, the Series 12 performed exceptionally well in indoor cycling, achieving nearly identical readings to the Polar H10 ECG chest strap. This high level of accuracy in a wrist-based device is important as it indicates the potential for improved health monitoring in everyday settings.

However, the accuracy during weightlifting was slightly lower compared to other activities, with a correlation of 0.97. While this is still commendable, it highlights the challenges wrist-based sensors face during strength training, suggesting that further refinements may be necessary.

The results from the Series 12 are broadly comparable to the previous Series 11, with minor variations noted during running sessions. This suggests Apple may still be fine-tuning the algorithms for the new sensor, which could lead to further improvements in future iterations.

Overall, the findings from The Quantified Scientist's tests could influence future design and development decisions in wearable health technology, as engineers may need to consider the varying performance of sensors across different types of physical activities.