45 Minute, 4.75 Mile Treadmill Routine:

Time Speed Incline
0-2 4.0 1%
2-5 6.0 1%
5-10 6.5 1%
10-15 7.0 1%
15-20 6.5 1%
20-25 7.5 1%
25-30 6.5 1%
30-35 7.0 1%
35-40 6.5 1%
40-43 6.0 1%
43-45 4.0 1%
Total: 4.75 miles

This routine goes by quickly, is challenging and the change of pace keeps things interesting, without having to constantly be changing the speed on the treadmill.