Vertical loading rate

Also known as: VLR, impact loading rate

How quickly impact force rises at the moment your foot strikes the ground.

Why it matters

Vertical loading rate is one of the metrics most consistently linked to bone stress injuries like tibial stress fracture, making it a useful early-warning signal.

What it means

Vertical loading rate is associated with tibial stress fracture risk. Increasing cadence by 5–10% typically lowers loading rate without requiring a foot-strike change. It rises sharply with overstriding and a straight-knee landing, which is one of the main reasons cadence work is recommended so often as a first-line fix for lower-leg injuries.