Polar has been at the forefront of producing reliable heart rate sensors. Polar heart rate monitors provide accurate heart rate measurements. This allows you to fine-tune your training schedules and train more focused on endurance, for example. Polar has heart rate monitors with chest straps and meters with bracelets. Choose a chest strap for the most accurate results. Do you wear a sports bra or do you easily suffer from skin irritation? You probably prefer a heart rate monitors with bracelet. 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.