By chance have you heard of a company called "Frappier Acceleration"? i.e. "Acceleration Indiana" is a local branch.
Frappier Acceleration Sports Training
One type of their training consists of short term bouts of sprinting on various degrees of incline..... some that are really freakin steep. It is very unorthodox... the athlete stand next to the already at full speed treadmill, and actually jumps on running. They run a prescribed time (usually a matter of seconds) and then jump off. I think I remember seeing speeds of 22 mph and maybe higher accomplished by high school kids, on a steep incline.
Sounded hokey to me at first.... but they have created a lot of faster, more agile athletes.
Have a look at that link.