Apple Watch Series 12’s 60x Heart Rate Claim: What Apple Counts, and the Baseline It Never Published

Apple makes two frequency claims for the Health Sensing System in Apple Watch Series 12: 60 times more frequent background heart rate readings than Series 11, and 24 times more frequent heart rate variability readings. The absolute rates Apple prints beside them are a heart rate reading every five seconds through the day and an HRV reading as...