Mid week long run pace

I had to run 12 miles on Thursday as my mid week long run. So I followed my previous week’s route down Metric to 183, then left on the frontage road for a mile, and return. The weather was better this week – not as humid. Half way I had a Clif Shot and some water. I tried to keep it easy as I have been told, but over time I found it harder and harder. My leg muscles were tight. Again I felt weak. I timed myself. I finished in 1:54:56 or about 9:35 minutes/mile which is not my marathon goal pace of 9:10. So I felt it was again a crappy mid week long run. What am I to do? My self-answer… I’ll just keep going, and I’ll see how I do this weekend for the 20-miler.