Pace.

I can't run slow.

I am not boasting and in fact it might be a problem.
Tonight on the second run of my marathon training I was supposed to be running a slow 4 miles. When I finished it turned out to be a run at my normal pace of 7:30 minutes per mile.
This is fine at the moment but what will happen when I start doing the longer runs? These are usually on a Sunday, this weeks being 12 miles. I will be OK to start with and of course I will naturally slow down as I get more tired but setting off too quick could prove to be my undoing.
I think the trouble is that if I run slow I get home and feel that I haven't put in enough effort. I will have to try to pace myself for the rest of the week for fear of burning out too soon.

Here's the link to tonight's run.