You may find it useful to reference Matt's Pace Chart (http://www.skyrunner.com/pace.htm) to see how you on progressing during the simulation. Matt's Pace Chart takes into account the effect of altitude and the pace slows at higher altitude for the same slope. You should be gaining time in the later stages since your altitude remains constant on the treadmill. If not gaining time (or falling behind), you may want to slow your pace at the start to provide some reserve for the final miles. Although the PPA is only 13.3 miles, the 11% average slope makes in roughly equivalent to a marathon.