How to make your Apple Watch heart rate recordings more accurate
Tired of sweat interrupting your heart rate recordings? There's a fix.

Optical heart rate monitors like those found on the Apple Watch are accurate enough to gauge the intensity of a workout and keep a close eye on your overall heart rate. However, for some users who prefer a more precise heart rate report, the Apple Watch offers support for external heart rate monitors.
Fitness companies such as Polar and Scosche offer Bluetooth-equipped heart rate monitors designed to connect directly to a phone, or in this case, your watch.
Compatibility
The main thing you need to look for when heart rate monitor shopping is that the strap supports newer Bluetooth connectivity standards. Straps that don't use newer Bluetooth technology likely won't work with the Apple Watch. Of course, it's a good idea to check with the manufacturer of the strap to ensure there won't be any surprises.
Pairing process
If you've paired headphones to your Apple Watch, this process will be familiar. Before following the instructions below on your Apple Watch, check with the maker of your heart rate monitor for steps to put it into pairing mode.
With the monitor in pairing mode, do the following on your Apple Watch:
- Open Settings
- Select Bluetooth
- Wait for the watch to find available devices, and when your monitor's name shows up -- tap on it.
Once the two devices are paired, whenever the strap is turned on and connected to the watch, any exercise activity will default to heart rate readings from the strap instead of the watch.