I just tested the Apple Watch Ultra 3's heart rate tracking against a Polar H10 chest strap – here are the results
PositiveTechnology

In a recent test, the Apple Watch Ultra 3 demonstrated impressive heart rate tracking capabilities when compared to the Polar H10 chest strap, a device known for its accuracy. This comparison is significant as it highlights the advancements in wearable technology, particularly in health monitoring, making it easier for users to track their fitness levels effectively.
— Curated by the World Pulse Now AI Editorial System