How to connect an external Bluetooth heart rate sensor to Apple watch

I’ve had my Apple Watch ever since it came out on the market and while I am very happy with it (except the battery life perhaps), I’ve been super annoyed with the integrated heart rate sensor that is measuring the heart rate on the wrist. While it works fine when I am doing cardio like running or biking, I’ve been constantly having problems with it losing the heart rate when I am doing weight lifting or circuit training.

I gave my mom a Polar M400 last year and she’s not using the chest strap so I decided to “borrow” it from her (and never give it back ๐Ÿ™‚ ) to use it for resistance training. Today was the first day that I got to test the Polar H7 with the Apple Watch and I am super happy. The Apple Watch had continuous connection to the chest strap and the heart rate was finally accurate throughout the entire workout.

So how did I pair the chest strap with the Apple Watch? It was quite easy.

Go to the Settings on the Apple Watch.

Select Bluetooth.

The chest strap is listed below Health Devices and it’s shown as not paired.

Simply select it and it’s connected.

If you want to unpair the Apple Watch from the chest strap, select the “i” and hit “Forget Device”.

Just a quick final note: only Bluetooth 4.0 compatible HR chest straps work with the Apple Watch.


  • If the Polar H7 is paired with the Apple Watch but it is shown as Not Connected in Settings => Bluetooth, restart the Apple Watch.