Pair your compatible Forerunner 620 with the HRM-Run to get not only heart rate information but also real-time feedback about your running form.
HRM-Run has an accelerometer in the module that measures torso movement in order to calculate 3 different running metrics
Cadence : The number of steps per minute. It displays the total steps (right and left combined)
Vertical oscillation : The bounce in your running motion. It displays the vertical motion of your torso, measured in centimeters
Ground Contact Time : The amount of time in each step that you spend on the ground while running. It is measured in milliseconds
Product Reviews for Garmin HRM-Run Heart Rate Transmitter