Not as good a week as the previous ones. On Wed. I intended to do a 6 mi run but my left hamstring tightened up after about 10 min. Stretching and pressure helped only a little. I slowed down, shortened my stride and was able to get to just under 4 mi. However, at that point the hamstring turned from tight to painful, so I stopped running right away and walked home. I was able to walk with only slight stiffness, and then ride the Lifecycle with no pain. So I figured it was probably a hamstring cramp that would take a few days to loosen up (ref: The Runner's Repair Manual). I stretched carefully, iced it morning and night from then through end of week, and taped it up. The rest of the week was all crosstraining, no pain at all: Thurs and Fri, Lifecycle for 70 min each. Sat. walked @15:00/mi on treadmill, 15% incline for 45 min. Sun. elliptical 60 min. So at least I didn't lose aerobic fitness but I did miss a 12 mi long run. Fortunately I'm a week ahead of schedule since I did just under 12 mi last week. Hopefully I'll be able to do the 13 mi long run next week. 

On Mon. I carefully ran 3.7 mi @10:41 pace with no problems. The pace felt very slow - totally aerobic - but it was good to be running again. I'll take it as long run pace calibration.