Back Trouble

No big deal but my back is hurting a bit, especially when I bend down. It started yesterday after the 6-mile walk and instead of stretching right away I did some house chores. Lesson--stretch right away after a walk or run.

I'm still sticking with the new schedule, 3-miles today, though I didn't work in any strength training.

Mile 1 - 14:00         (8:42 min/km)
Mile 2 - 12:25         (7:43 min/km)
Mile 3 - 11:16         (7:00 min/km)
Total Workout - 37:42
Average Pace  -  12:34 (7:49 min/km)

I'm finally getting into the habit of starting out slowly and building up the speed. However, maybe I shouldn't be including the warmup in the average?