Sometimes running is just hard! Hubby and I went out to the hike/bike trail around the lake where our hotel is, downtown. And I just didn't feel that great today. So my first mile pace was good but it was downhill from there. (Pace on 3.13 mile course: 11:07 per mile. Total course length was longer with warm-up and cool-down walks.)
I was frustrated, but you know what? I feel better now than I would have if I hadn't gotten out there this morning. I'm more fit now, and more prepared for my next run, than I would have been if I hadn't gotten out there this morning. Even a "bad run" is a good workout!
I have been running for 4 months now, and my endurance is still building up, so I'm still affected a lot by my energy level, quality of sleep, etc. I'm consistent, though, three times a week. I'll keep up the consistency--the endurance will follow.