How It Works
- Start a workout on your Apple Watch. The watch reads your heart rate from its built-in optical sensor via an active HealthKit workout session.
- Your iPhone broadcasts over Bluetooth. Pulse Link relays heart rate data in real-time from the watch to the iPhone, which advertises a standard BLE Heart Rate Service.
- Your fitness equipment connects. Smart trainers, treadmills, rowing machines, and companion apps see your iPhone as a standard Bluetooth heart rate monitor — just like a chest strap.
Apple Watch iPhone Fitness Equipment
Key Features
- Standard BLE Heart Rate Monitor profile — compatible with any equipment or app that supports Bluetooth HR sensors
- Real-time heart rate from Apple Watch optical sensor
- 5-zone heart rate model with colour-coded zone indicator on watch and iPhone
- Up to 3 simultaneous BLE connections
- Background broadcasting — iPhone continues transmitting when locked or backgrounded
- 7 workout types: Indoor Cycling, Outdoor Cycling, Indoor Run, Outdoor Run, Rowing Machine, Cooldown, Other
- Energy Expended included in BLE payload for compatible equipment
- Zone 5 haptic alerts on Apple Watch (configurable)
- Automatic HR zone calculation from age and resting heart rate via Apple Health, or set manually
- Post-workout summary: duration, average HR, max HR, energy burned
- Workout data saved to Apple Health (optional)
Compatible Equipment & Apps
Works with any device or app that connects to a standard BLE heart rate monitor:
- Smart trainers: Wahoo KICKR, JetBlack, Tacx, Elite, Saris
- Cardio machines: Treadmills and rowing machines with Bluetooth HR pairing
- Apps: Zwift, MyWhoosh, TrainerRoad, Rouvy, JetBlack Trainer, Kinomap, and more
System Requirements
- Apple Watch Series 4 or newer (paired with iPhone)
- iPhone with iOS 17.0 or later
- watchOS 10.0 or later
- Bluetooth must be enabled on iPhone
FAQ
- Do I need a chest strap?
- No. Pulse Link uses the Apple Watch's built-in optical heart rate sensor.
- Does it work with Zwift / MyWhoosh / TrainerRoad?
- Yes. Pulse Link broadcasts a standard BLE Heart Rate Service. Any app or device that supports Bluetooth heart rate monitors will work.
- How many devices can connect at once?
- Up to 3 simultaneous BLE connections.
- Does it work when my iPhone is locked?
- Yes. The iPhone continues broadcasting over Bluetooth in the background, even when the screen is locked.
- Why does the app need HealthKit permissions?
- The Apple Watch reads your heart rate via HealthKit during workout sessions. Your age and resting heart rate are used to calculate personalised heart rate zones. Workout sessions are optionally saved to Apple Health.
- Does the app send my data to the cloud?
- No. All data stays on your devices. Heart rate is transmitted locally from watch to iPhone to your fitness equipment. There are no accounts, analytics, or server-side components.
- Which Apple Watch models are supported?
- Apple Watch Series 4 or newer running watchOS 10.0 or later.
Support
For help or questions, email pulse-link@humblemars.com.