Bluetooth heart rate monitors measure your heart rate and show it on your favorite Bluetooth device. Connect the heart rate monitor to your smartphone, smartwatch, or a fitness machine via Bluetooth. You can adjust your workouts thanks to accurate heart rate measurements. See whether you're training in the right heart rate zones this way, and work on your endurance in a more focused way. Want to go swimming with a Bluetooth heart rate monitor? Choose a waterproof heart rate monitor.