Pair your compatible Garmin device with the HRM-Run to get your heart rate & real-time feedback about your running form. HRM-Run has an accelerometer in the module that measures torso movement to calculate 3 running metrics: Cadence — the number of steps per minute. It displays the total steps (right & 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 your foot spends on the ground while running (measured in milliseconds).