I ran 4 miles this morning, and I just ran 3 miles. I kept it under 10 just to test it, and I feel good. I felt refreshed going into the 2nd run. My focus is to double my long runs, get up to 14 miles total, 7 in the day and 7 at night. Anything more than that would defeat the purpose.
Usually, when I do a single run day, and go over 6 miles, my body's yellow alert signal starts going off: slight fatigue in the calves, not feeling fresh, and I start thinking about how many miles I have to go ( which is a clear sign that my performance is about to drop).....
The body generates a lot of energy during the daylight, so getting that run in the morning allows my body to quickly recover after the run, and have some good energy for my night run.
Monday: Long run , double 7/7
Tuesday: Rest ( strength train)
Wednesday: 4 x 1200 ( or 4 x 1 mile) - 2 mile warm up and 2 mile cool down
Thursday: 6 mile easy run
Friday: Rest ( strength train )
Saturday: 5k or 10k race...if there is no race, 10 mile easy run
Sunday: Rest
Total: 37 to 40 miles a week.