Most people who have ever trained for a marathon have heard of "Yasso 800s". I don't subscribe to Runner's World any more and I haven't for years, but I did subscribe in my road racing days. I think that the linked article above was the most valuable article that I ever read in the magazine.
Bart Yasso didn't write the article, but his name is forever attached to the workouts. A couple years ago, I talked to Bart at the runners' expo for the Vermont City Marathon. We were mostly talking about ultras (his wife is an ultrarunner), but I had to bring up the topic of his eponymous workout. He told me that he ends up discussing that workout with more runners than any other topic about running.
Anyway, in 1995, I used a months-long progression of Yasso 800s in marathon training. My final workout of 10 x 800 predicted a marathon time of 2:57:18 and I ran 2:57:35. So, I was sold. Over the years, I've seen many runners argue about the validity of the "predictive" aspect of this workout. I think that some people believe that if they can go out and run 10 x 800m at 3:00 each, they should be able to run 3:00 for the marathon according to the article. I read the article a slightly different way, seeing the workout as not only predictive, but as an integral part of training.
The way I use the workout is to start at 6 x 800, and move up one rep at a time until I hit 10, but I do each number of reps twice. All told, I do 10 workouts of 800 meter repeats. By the time I get to 9 x 800, I do the workout only ever other week, because it takes so much out of me.
So, I've picked a target marathon on 11/9 - the Harrisburg (PA) Marathon. I want to do my last 10 x 800 workout about 3.5 weeks before the race. At that point in time, I hope to be able to average 3:15 or better per repeat. I "only" need to run 3:30 to qualify for Boston, but I want to be in better than 3:30 shape in case something doesn't go quite right on race day.
Last night was 6 x 1/2 mile on a dirt track. I'll move to a higher quality 400m track for some of the workouts, but the closest track to my house is an old dirt track at Norwich University. I expected to average about 3:25-3:30 after not being on a track for a while.
My first repeat was 3:11 but I knew I'd pushed too much. My second was 3:15. Then, 3:22 - a bad trend. Then, I continued to slow down, with a 3:22, 3:25, and 3:26. But, my average was 3:20 and the median was 3:22, which was better than I expected.
In 2006, I ran the Vermont 100 in 27:20 or so. After recovering for about 6 weeks, I decided I wanted to try to qualify for Boston that fall. I picked a late year marathon, run on 12/23. I did OK for 10 miles, struggled a bit to 15 miles, and then gradually faded and quit at mile 22 when I had no chance of qualifying for Boston. As I look at my training logs from that fall, one thing stands out. I did the long runs I needed to do. I did tempo work and I did marathon pace work. My weight was low enough that I should have been able to qualify. But, I didn't do any Yasso 800 workouts - not one. This time around, I hope this workout makes the difference.