The Importance of Speed in Sprinting

Sprinting is about ground reaction force. When you're sprinting against the surface that doesn't have a stable surface of your foot's going into the ground and the force is dissipating out, you're no longer working speed. You can get some gains by doing a little bit, like not enough. But when you go above and beyond and you get too much of a stimulus, your body just shuts down. That stimulus is too far out of reach, you can't adapt. Exactly. In fatigue and injury.