Although the will be some natural variation in cadence and stride length at the extremes (jogging and sprinting), you will find that the most efficient runners stay pretty consistent regardless of effort. Many people assume that running fast is about pushing off of the ground with more force. However, running (when using good form) is more like a controlled fall. It's really more about your bodies position throughout the movement and a coordinated relationship between your nervous system and muscle fibers to support forward motion through the use of gravity. When using good form, you begin to lean forward (not at the hips), increase you knee drive, and swing your arms farther back and forth, as you speed up. Your body covers a greater distance over a shorter period of time due to the increased effort being committed to maintaining a the sequence of poses and fluidity of form that keep you from falling on you face.
Although there are lots of ways to conceptualize this, the POSE method makes the most sense to me. Google it if you want a better understanding of how this works.
Yeah. I was wondering what thumbs was. LOL. I thought maybe some special training technique.