Dunno what you posted, but anyway....
When I was in boot camp, they boosted our running stamina by doing a lot of short sprints and working our legs to exhaustion with cardio type exercises. Between the time I left for boot camp and the time we did the 3 mile timed run in boot camp (maybe 2 1/2 months), I dropped 2 full mintues off of my run time, from 23 1/2 minutes to 21 1/2. A friend of mine that went through boot camp with me dropped almost 3 minutes off of his run time. He was down to 19 something on the 3 mile run by the end of boot camp.
Btw, the Marine Corps says that 18 minutes on the 3 mile run is a perfect score. Turning 6 minute miles is pretty damn fast, and I even considered my best run of 21 1/2 minutes to be fast. ~7 minute miles are not fun.