How to pair an external heart rate monitor to Apple Watch

[iMore.com]

Although the Apple Watch has a built-in heart rate sensor, more serious training may require some external help.
While your Apple Watch's heart sensor should perform just fine for passive monitoring, anyone training or in need of much more accurate data may be better off with a heart rate monitor strap. Luckily, the Apple Watch supports connecting a Bluetooth enabled strap or monitor. Once you pair it within Settings, you're ready to go!

Full story from the iMore Blog...