Big Dreams today - down the toilet. Ran 8 minute warm-up mile then a 6:40 mile, 3:15 1/2 mile, 1/2 mile jog, 6:40 mile, 3:15 1/2 mile, 1/2 mile jog, left calf crashed on next mile. Jogged it in to the barn. May be a shoe-engineering issue - will try some tricks today and tomorrow after icing. Doggone it.