The Apple Watch® boasts a phenomenal heart rate sensor – so why use additional gear when you already have one on your wrist?
Using the HRM Heart Rate Monitor app, you can simply and reliably use your Apple Watch® to track your heart rate with your cycling computer.

Unlike other heart rate monitoring solutions, you don't need any additional hardware. With the HRM app, all you need is your Apple Watch® and your iPhone® to reliably send heart rate data to any compatible bike computer via Bluetooth Low Energy (BLE). 
The HRM app is compatible with almost any BLE-equipped bike computer. Please find the up-to-date compatibility list here: https://dominikmaglia.com/hrm-app-user-guide/#device-compatibility

You don't even need to worry about carrying your phone in your hand - the app works seamlessly without any impairment to your phone, allowing you to focus on your ride.

The HRM app simply reads heart rate data from the Health app using HealthKit and your data is stored securely in the Health app. It does not create any data. No complicated settings or redundant tracking of your workouts and training zones. The HRM app provides just a simple and reliable alternative to traditional chest straps.

Mind that this is a paid app that requires a subscription. But worry not: You can test the app for free for seven days. If you don't like it or there's an issue with your setup, you should cancel the subscription before the trial ends and you won't be charged a dime.

The subscription is auto-renewable and automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. Your account will be charged for renewal at the price listed within 24 hours prior to the end of the current period. Subscriptions made on iOS devices can be managed and auto-renewal turned off in Account Settings for your Apple ID after purchase. Once purchased, refunds will not be provided for any unused portion of the term. But no need to worry, you may cancel at any time.

You can find our terms of use on my website: https://dominikmaglia.com/hrm-app-terms-and-conditions/

Be sure to have the app installed on both your Apple Watch® and your iPhone®. It does not work with just any of the two.