Ground contact time (GCT)
Also known as: contact time, support time
How many milliseconds your foot stays on the ground during each running step, and what a healthy range looks like.
Why it matters
Ground contact time is one of the clearest signals of running economy — shorter, springier contacts waste less energy and place less strain on the calf and Achilles.
What it means
Recreational runners average 240–280 ms of ground contact at easy pace; elites are often below 200 ms at race pace. Shorter contact time correlates with better running economy and elastic energy return from the Achilles tendon. GCT typically rises as pace slows and as fatigue sets in, making it a useful signal for whether your stride is breaking down late in a run.
Related reading
The complete guide to running form analysis