I've been asked how I trained to run my first marathon under 3 hours, what I would've done differently and how I would do it now. Each runner is different and I doubt my experience would mean much to others, but there may be some interesting points.
My first sub-3
My first marathon finishes were in 3:20, 3:17, 3:05, 3:41 (stress fracture) and 2:42; I never really improved after that. Where did that sudden improvement come from? Well, I went from being 16 years old to 20, which I think means more than training or experience. I'd run a 10K in 32 and was regularly beating 2:30 marathoners in short races, so I thought I could probably run a 2:30 in a year or two and just went out and "winged" it, ran by feel and without expectations. The weather was ideal (55 degrees at the start, 65 at the end, not the 35 that people keep saying "but runners LIKE that!), I knew personally 100 of the 120 runners who beat me that day and probably a thousand of the 3500 behind me, there was someone cheering for me by name at almost every intersection. It was glorious. It was one of those perfect days, though I struggled a bit in the second half and slowed from about a 2:36 pace. I thought it would be like that forever.
My last attempt at 3
Nine years ago was my last serious attempt at breaking 3 hours. I'd started taking care of my mother, who had Alzheimer's, and I knew I wouldn't have the time to train again for years, so this was my last shot. At this point, I could leave her alone for a while and I ran a 3 mile loop and checked on her after each loop. I wasn't sure what kind of marathoning shape I was in, as I hadn't run one in a while. I managed to run a series of warm-up races of 1/2-marathons every-other week, which I tried to do at marathon pace and comfortably finished in 1:27-1:28. Wondering if perhaps I was racing these all-out, I intentionally ran a half hard and finished in 1:24. Three weeks before the marathon, I ran a 10K in 37:54 and knew I was fast enough and had had some decent marathon paced runs, plus decent mileage and long runs.
The problem: I started preparing my mother for the race a few days beforehand. She kept saying "Please don't do this! I'll pay you whatever it cost you, not to run." Great, just great... running with guilt. I asked my sister to drive me to the start and from the finish and to watch Mom during the race; she thought it would be an ordeal (and this was when Mom could walk a mile and carry on a conversation, not when you had to feed her and change her diapers), but she agreed. More guilt.
I hadn't slept well in days. Later, my mother would stop being able to tell day from night and then I didn't really sleep for 3 years, but this was still early. It was mostly pre-race jitters. I was tired and frazzled before I started.
With one last "Don't Go!" I headed to the start line. Eight miles later, I crumbled. Hit the wall at 8. Staggered and walked 18 more miles. Finished in 3:16 (I think).
So how would I personally train to run 3:00 again, if I thought I could do it (and I don't)?
The basics are that I'd do my easy runs at about 8 min./mile and try to tun 66 miles in an average of 75 minutes per day, with at least 75 minutes (and preferably 90-105) at marathon pace or better per week. Long run would be 2 1/2 hours, give or take 15 minutes.
One plan I'd had went as follows:
Monday: 6 miles @ 8
Tuesday: 6x 1 mile in 6:00 with 600 meter (3 min.) intervals, with 2 warm-up and 2 cool-down
Wednesday: 6 @8
Thursday: 16x400 in 85 with 400m (2 min) intervals, plus warm-up/down
Saturday: 10 @ 7 (about mar. pace)
Sunday 18 @8
As I progressed the weekend runs would evolve into
Saturday: 10 @ 7 plus 10 very easy
The problem with this was that, after the hard section on Saturday, I'd slow to a shuffle and I was essentially teaching myself to go out hard and crash and burn.
A second plan
Monday: 4 in 30 min.
Tuesday: 90 min. with 7x 1 mile in 6:50
Wednesday: 30 min.
Thursday: 90-120 min. (12-16 miles)
Friday: 30 min.
Saturday: 90 min. with 7 miles at mar. pace
Sunday: 135-165 min. (18-22 miles)
This was an attempt to rid myself of the 10K pace track work and focus on marathon pacing, with a second longish run per week. The trouble here was one that's dogged me throughout my questionable marathon career: being able to run fast or far, but not fast during long runs. That leads to the next.
Monday: 30 min.
Tuesday: 90 minutes with intervals
Wednesday: 90 minutes with hills
Thursday: 30 min.
Friday: 30 min.
Saturday: 165 min. with 7 @7min./mile
Sunday 90 min.
The Saturday run would progress through the season by moving the marathon-paced portion from the beginning to the middle and then to the end of the run. The back-to-back longer runs I felt would help me with my endurance.
This third plan has its appeal, but the problem is that I'd end up being able to run only 7 miles at marathon pace (for some reason, training is very specific for me). Looking at how I trained for my first good marathon, I did no intervals or hills; I raced myself into shape and only ran fast on occasion, rather than regularly, but I ran a lot of miles and I did them pretty fast on a regular basis. Going "old school," here's what my training would look like:
Monday: 11 miles
Wednesday: 11 w/ 6 at mar. pace
Saturday: 17 w/ 10 @ mar. pace or race (8K-1/2 mar.)
Wednesday: 11 w/ 6 @ mar. pace
The monotony of the 11 milers isn't written in stone; some days would be a little more, some a little less; the number of miles at marathon pace could also be varied. The easy days have become off days, so the other runs become longer and more specific to the long race. The first Saturday run would have the faster section at the end, unless it was a race day, in which case it would be at the beginning. The second Saturday run approaches 3 hours in length and the next day's 11 would be a barometer of how hard or easy it was.