The long run is your training program for the marathon or the half marathon.
What is a long run?
The long run starts with the longest distance you’ve covered within the last two weeks and increases by one mile on a weekly long one up to 8-10 miles. At that point, you’ll shift to running long every other weekend, increasing by two miles each time. For the marathon, once you reach 18 miles, increase by three miles every third week. For the half marathon, once you reach 8 miles, increase by two miles every third week.
I’ve read a couple of Jeff Galloway’s books about running. He is realistic, low key and explains concepts well. Jeff is a big, possibly the biggest, proponent of mixing walking into running early on in any training or race because it lets you run further with a smaller chance of injury.
I just found this article about long slow runs and why they belong in your running schedule.
My top tip for long slow runs: stop at a corner shop every so often and buy a sugary drink or a banana to help keep some fuel in the tank.