HRM Heart Rate Monitor App User Guide
This guide shall provide everything you need to know to use the Apple Watch® and the iPhone® App to stream heart rate to a cycling head unit such as a Garmin Edge, Wahoo ELEMNT, or others.

Contents
How The App Works
The HRM app emulates a heart rate monitor by implementing the standardized Bluetooth SIG Heart Rate Profile and Heart Rate Service and transmits heart rate data collected by your Apple Watch® to any compatible BLE device.

It requires both the Apple Watch® and the iPhone® to do so: The iPhone® offers Bluetooth connectivity, whereas the Apple Watch® takes care of the heart rate measurement and transmits it to the iPhone®.
How To Use The App
To receive the heart rate measurement from your Apple Watch®, the following steps are required:
- Open the HRM app on your iPhone®.
- Open the HRM app on your Apple Watch® and press "Start".
- Connect the HRM app to your bike computer. This usually requires sensor pairing as described below.
- Perform your workout session. Track it on your bike computer.
- When you're done with your session, press "Stop" to stop the frequent collection of heart rate on the Apple Watch® and its transmission via Bluetooth.
How To Connect Your Bike Computer
As soon as the iPhone® app is first opened, it will start broadcasting its Heart Rate Service to compatible BLE devices. The app will then also exchange Bluetooth messages in the background, as long as your session is activated by pressing "Start" on the Apple Watch® and the iPhone® app shows radiating blue circles.
Connect to Garmin Edge
The exact sensor pairing procedure depends on your Garmin Edge model, but the following is true for most devices:
- Open the HRM app on your iPhone®
- Open the HRM app on the Apple Watch® and press "Start"
- On your Garmin, go to "Main Menu" / "Settings" > "Sensors" > "Add Sensor"
- The HRM App should now be discovered by the Garmin device
If you're starting a new workout and the heart rate doesn't appear on your Garmin device (and your Garmin doesn't appear under "Bluetooth Connection" on your iPhone®), you may need to toggle "Enable" within "Settings" > "Sensors" > "Heart Rate".
Connect to Wahoo ELEMNT
The following procedure should be applicable for all Wahoo ELEMNT ROAM & BOLT devices:
- Go to the settings menu, then scroll to "ADD SENSOR"
- Make sure to have the iPhone® app open and press "Start" on the Apple Watch®, then bring your iPhone® close to your ELEMNT
- Select "ADD" – the sensor with the highest signal strength will be displayed, which should be your iPhone® – and then select "SAVE" to pair the HRM app sensor
If you need further help, you can find Wahoo's official instructions here.
Device Compatibility
Unfortunately, not all bike computers allow the HRM app to connect via Bluetooth. Some devices seem to block any attempt from a phone to connect and it seems like there's nothing I can do other than just curate the following lists:
Compatible Devices 💪
- Garmin Edge 130/130 Plus
- Garmin Edge Explore
- Wahoo ELEMNT Bolt V2/Roam
- ... maybe yours? Please let me know!
Incompatible Devices ☹️
- Garmin Edge 530/830/1030/1040 Solar
- iGPSPORT iGS630 / iGS520
- ... maybe yours? Please let me know!
Frequently Asked Questions
Do I need to press "Start" and "Stop" on the Watch?
Yes. Doing so will start the frequent collection of heart rate data and keep your session running in the background, i.e. also when either app is not visible.
Do I need to keep the iPhone® app open?
No. You can use your phone regularly while the HRM app is kept running in the background to send heart rate data via Bluetooth to connected devices.
Do I need to keep the Watch app open?
Yes. If you want frequent heart rate updates, the Watch app must be kept open during your workout session.
Having Issues or Feedback?
If you encounter any issues with my app or have feedback to share, please let me know via email:
I hope the app is helpful to you and serves you well. Happy training!
– Dominik