Running Dynamics

You can use your compatible fēnix® 3 device paired with the HRM‍-‍Run™ accessory or other running dynamics accessory to provide real-time feedback about your running form. If your fēnix 3 device was packaged with the HRM‍-‍Run accessory, the devices are already paired.

The running dynamics accessory has an accelerometer that measures torso movement in order to calculate six running metrics.


Cadence is the number of steps per minute. It displays the total steps (right and left combined).

Vertical oscillation

Vertical oscillation is your bounce while running. It displays the vertical motion of your torso, measured in centimeters.

Ground contact time
Ground contact time is the amount of time in each step that you spend on the ground while running. It is measured in milliseconds.
NOTE: Ground contact time and balance are not available while walking.
Ground contact time balance

Ground contact time balance displays the left/right balance of your ground contact time while running. It displays a percentage. For example, 53.2 with an arrow pointing left or right.

Stride length

Stride length is the length of your stride from one footfall to the next. It is measured in meters.

Vertical ratio

Vertical ratio is the ratio of vertical oscillation to stride length. It displays a percentage. A lower number typically indicates better running form.