Heart Rate Chest Strap with Activity App

Hi

Apple Watch already has a built-in heart rate monitor, that takes readings continuously when recording workouts via the Workout app:

• Work out with your Apple Watch - Apple Support
• Your heart rate. What it means, and where on Apple Watch you’ll find it. - Apple Support
• Get the most accurate measurements using your Apple Watch - Apple Support

If you are unable to get reliable readings from the built-in sensor (which may occur for various reasons, as detailed in the support articles linked above), then various Bluetooth chest strap heart rate monitors can be paired directly to your Apple Watch. When connected, an external sensor will be used automatically instead of the built-in sensor:

Use Bluetooth accessories with Apple Watch - Apple Support

Examples of chest strap monitors that other users have reported having used successfully with Apple Watch include wahoo TICKR and Polar H7.

Whilst Polar H7 can be used in conjunction with the Polar Beat app, users have previously reported using it successfully when paired directly to Apple Watch instead, without using the app.

You may wish to confirm this directly with Polar before making a purchase.