A heart rate monitor with chest strap displays your heart rate data very accurately. You measure your heart rate just like a sports watch, only now you place the meter right next to your heart. This way, your actual beats are measured for an even more accurate result. The sensor measures your heart rate via electrodes on your chest and sends this data to your linked smartphone, smartwatch, or fitness device via ANT+ or Bluetooth. This way, you can see your heart rate data during and after your training. Do you also want insight into your average speed, distance, and cadence? Use the heart rate monitor in combination with a sports watch.