I try not to run four or five days before a big race. In this case, I'm not racing but pacing, but yeah, I'll be on my feet for half a day or so. I won't run anymore, but I will spin on a stationary bike and swim a few miles worth of laps instead. That ought to keep my muscles (overall) warmed up while leaving my running stuff fresh for the weekend. I think.
My peak weekly mileage was like 55, but I do some different stuff, especially this time around. I did a lot of night running, which is slow on the trails. And I did almost all of my running when I was fatigued. Either at the end of a workday where I get up at 4am, walk around a power plant all day long, and then run at 8pm that night. Or doing back to back to back runs where I start off tired on a Friday (previous scenario) and then run on Saturday and Sunday. The logic here is that my body is now trained to keep moving even when I am DFT (dead fvcking tired) and in pain. I also did a few longish runs over the summer, the longest being 33 miles.
So I have to be confident that I've done all I can with the time I've had available to me and that I'm ready to go on Saturday. But I am feeling jittery, like I might have overlooked something.