What is ground contact time, and does it matter?

How long each foot stays on the ground, typically 200–300 ms. Shorter contact times correlate with better economy, but they are largely a consequence of speed and structure rather than a lever.

Ground contact time is the interval between footstrike and toe-off, usually between 200 and 300 milliseconds for distance running and falling as speed rises. Elite runners at race pace produce notably shorter contact times than recreational runners at their own race pace — but they are also running considerably faster, which accounts for much of the difference.

The correlation with economy is real. Shorter contact generally means less time spent applying braking force and better use of elastic energy stored in the tendon on landing. Contact balance between left and right is also monitored as an asymmetry indicator, though its clinical usefulness is contested.

Where this gets misread is causality. Shortening contact time deliberately, by trying to "get off the ground quickly", tends to raise cadence and reduce stride length in ways that often make economy worse. The runners with short contact times generally have them because of tendon stiffness and years of accumulated adaptation, not because they thought about it.

The intervention with actual evidence behind it is heavy resistance training and plyometrics, which increase tendon stiffness and improve the stretch-shortening cycle. Contact time falls as a consequence — which is the useful order of operations.

Glossary: Running Economy (RE)