When it comes to measuring heart rate and calories burned, not all fitness trackers are created equal, based on the findings of a scientific study that pitted the top wearables on the market against each other.

The in-depth study conducted by researchers at Stanford University was published today, revealing that Apple Watch is the most accurate wrist-worn tracker on the market, but it’s still far from perfect.

Fitness fanatics that want a good heart rate reading from their wrist better get an Apple Watch.

A new study of the four most popular wearables on the market found Apple Watch to be the most accurate smart watch for tracking heart rate. And it wasn’t even close.

Fitness trackers are a leaky haven of data for hackers, according to a new study that found if you want a device with a high security rating, you better buy an Apple Watch.