Polar has been at the forefront of producing reliable heart rate sensors for years. It's not without reason that scientific studies often choose a Polar heart rate belt when doing research. Did you choose a Polar heart rate belt? You can be sure that your heart rate measurements are accurate. You can connect the sensor to your sports watch or smartphone via ANT+ or Bluetooth. This way, you view your heart rate during exercise and you can train based on your heart rate zones. Afterwards, you can analyze your heart rate in the app.