Polar was the first to invent heart rate sensor, a personal monitoring device that allows one to measure heart rate in real time. Keep a regular check on your heart rate with Polar’s trusted heart rate sensors which is recognized and widely accepted by the users and researchers across the globe. Training with a heart rate monitor helps you to know how your body has been performing and what areas it needs to improve. Polar heart rate sensors connect to your sports watch, or bike computer, gym equipment or Polar Beat app, or any other of your favorite fitness apps with Bluetooth® and ANT + to display live heart rate during all your workouts.