While I am a pretty athletic guy, and I'm not afraid to try some seriously difficult strength exercises, I've never been good at quickly running long distances. I usually did well on my 1.5-mile run because I could sprint for 3-4 laps and then just held on until I crossed the finish line. Although this worked, it wasn't fun and I found myself physically drained once the PT test was over with.
So, after doing this a couple of times, I decided to change my running equipment. I switched from regular running trainers to the Nike Free shoes, which helped a little, but didn't do much for my chronic running injuries (mostly shin splints). After a bit more research, I decided to try minimalist shoes (specifically the Vibram Bikila LS). While these shoes allowed me set my fastest run time (11:24), and helped me get rid of my chronic running injuries, it only slightly reduced how tired I felt after I was done running.
As I do with all my difficult problems, I started buying books to research a solution. After reading about the the Chi, Pose, and Evolution running techniques, as well as some running and endurance physiology theory, (1,2) I managed to assemble five changes to my training that have helped me complete the running portion of my PT test without feeling tired afterwards.