Hacking Bluetooth Sports Tech for Fun and Profit — Part 5: How Accurate Is DIY HRV From a Hacked WHOOP?

Six nights, 356,000 records, thirteen algorithm variants, and a surprisingly honest answer from the data. In the previous posts I documented the WHOOP&apos;s proprietary BLE protocol, built a passive daemon that downloads buffered sensor data overnight, and decoded the 93-byte historical records, including heart rate, RR