Stryd Duo delivers new biomechanical metrics tracking the differences between the left and right sides of your body.

These new “balance” metrics are being delivered with leading, Stryd-fidelity for the first time, allowing you to track your trends over time to learn more about your running progression and to understand quantitatively what works best for you.

Ground Contact Time (GCT), or Ground Contact, is the amount of time per stride that a runner's foot is touching the ground, in milliseconds. The starting trigger of a runner's ground contact time will vary depending on the runner's gait (heel-strike versus midfoot-strike versus forefoot-strike) but will always end at toe-off (full body removed from the ground, now in the swing phase of the gait cycle).

Ground Contact Time Balance from Stryd Duo reports how much longer or shorter one foot remains on the ground relative to the other, in terms of a percentage.

Vertical Ratio is calculated by dividing the vertical oscillation by their stride length. It is expressed as a percentage.

Vertical Oscillation (Vert. Osc.) is the vertical movement of a runner's center of mass between steps when running. A human's center of mass is typically at the pelvis or hip, so an easy way to think about vertical oscillation is the vertical rises and fall of a runner's pelvis over one gait cycle (expected minimum vertical position at mid-stance of ground contact, expected maximum vertical position during float period). Typical Vertical Oscillation values will range from 3-15cm.

Vertical Oscillation Balance from Stryd Duo reports how much higher or lower one side of the body rises relative to the other, in terms of a percentage.

Leg Spring Stiffness is a model of elastic energy in the leg, assuming it acts like a spring. It is the maximum vertical force a person generates in a step divided by the displacement during ground contact time.

Leg Spring Stiffness Balance from Stryd Duo reports how much more or less Leg Spring Stiffness is modeled on one side vs the other, in terms of a percentage.

Impact Loading Rate is the initial rate of increase in vertical (or perpendicular) force as a runner contacts the ground with their foot. It is reported in the units of body weight per second (bw/sec). This is an overall metric of how much load is being applied to the lower body over time. Higher values mean force is being applied at a faster rate. Lower values mean force is being applied at a lower rate.

Impact Loading Rate Balance from Stryd Duo reports how much more or less Impact Loading Rate is being exerted on that side of the body by the ground.