For my long runs, I frequently run a 3.15 mile loop around a local park and golf course. The advantages are that it's flat, there is minimal traffic, there are public restrooms, and I can leave a cooler in the car stocked with with Gatorade and whatever else I want that day.
The disadvantages are that it's boring and that by my sixth loop, I really feel tempted to cut the run short. Every excuse possible went through my head on Saturday - 19 miles is long enough to develop the requisite amount of fitness, I don't want to injure myself, etc., etc. But I had told you guys that I was going to run 25, and I sure didn't want to come back with only 19 to show.
It was pretty much all mental, though. By the time I finished that lap, I was raring to run my heart out for one last lap and see what was left in the tank. I held back for a slow mile 23 (10:55), then ran mile 24 in 10:01, and mile 25 in 9:48. OK, so there wasn't much left in the tank! But I finished without injuries, and with an overall pace of 10:26, which is faster than any run over 15 miles I have done at the past.
I'm going to run five miles further, but I'm hopeful that cooler weather, rested legs, better pre-race nutrition, better in-race fueling, and a dose of adrenaline will push me along to an even faster time.
After which, I just have to figure out how to increase my speed to beat you guys in the marathon.