Heart rate is not detected. What can I do?Applies to: Polar Team Pro shirtMake sure that: The Polar Team Pro shirt fits fairly tight so that the electrodes are firmly against your skin. If the shirt is not tight enough around your chest, heart rate may not be detected. The Polar Pro sensor is attached correctly. The Polar logo should be upright and both ends of the sensor should be snapped firmly into place. Your Polar Pro Sensor battery is not empty.