Vertical Oscillation

Why this matters

Running is forward motion, but every step also throws the body upward — and that vertical travel is largely wasted work. Energy spent lifting the centre of mass has to be spent again on the next step, and none of it moves the runner down the road. So a smaller bounce, for the same pace, is a more economical runner.

Under ~8 cm of rise-and-fall is efficient: energy goes forward rather than up. Around 8–11 cm is a typical bounce for recreational runners. Above ~11 cm the runner is paying a vertical tax on every stride — and it rarely travels alone, because a big bounce usually pairs with overstriding and a low cadence, each of which feeds the others.

What good looks like

The head and torso stay on a nearly level line across the stride cycle — the athlete looks like they're gliding rather than pogo-ing. A quick, light cadence keeps the ground contact short, so the body rolls over the foot instead of being launched off it.

Common faults

• High bounce (>11 cm) — wastes energy vertically. Usually a symptom, not a cause: look upstream at cadence and stride length.
• Overstriding — reaching the foot out in front converts the leg into a lever that vaults the body up and over, directly inflating oscillation.

Coaching cues

• "Run tall and quiet" — a higher, softer cadence naturally flattens the bounce.
• "Skim, don't spring" — bias the athlete toward forward travel rather than pushing up off the ground.

How it's measured

This is an auto-measured, whole-clip metric — there are no points to click. Select the tool, make sure the athlete's height is set in their profile (the reading is scaled from it, so no object calibration is needed), and tag the clip's Lateral side. Press ✨ Auto-measure: it reads the near (unoccluded) leg's stance bounce and draws the band on the frame with the average in cm. Run it on both a Lateral·L and a Lateral·R clip to get the left/right pair and its asymmetry.

Related measurements

• Cadence — the single biggest lever on vertical oscillation; raising cadence for the same pace flattens the bounce.
• Step Length — the other half of the same trade-off; a long, reaching step vaults the body upward.
• Stride Angle — overstriding shows up here first, as a foot planted well ahead of the body.