When I first started training to BQ (qualify for the Boston marathon by running a 3:40), I figured a good approach would be to add more mileage to my program. It seemed like the most logical thing to do because almost all running literature says that the more mileage, the better your endurance at the marathon. As many of you know, I spent the summer following a plan that involved a lot more mileage than I was used to.
However, most of these extra miles were run at a slow pace. Speedwork was done once every 7-10 days. In the past, I used to do speedwork twice a week, and I am pretty sure that's how I was able to eventually decrease my marathon time from 4:46 to 3:51. The difference in training mileage between the 3:51 marathon and the 4:46 marathon is not that much. I think that I just got faster and faster the more speedwork I did.
I came to the realization that I need to continue to favor speedwork over mileage if I want to run a 3:40. This contradicts what most experts and most fast marathoners would advise, but every person has unique training needs based on his/her natural strengths and weaknesses. I believe that my natural strength is endurance, and my natural weakness is speed. Most people who run 5Ks and 10Ks at my pace have much slower marathon times. And most people who have similar marathon times to me run much faster 5Ks and 10Ks.
Most people say that the McMillan Running Calculator is only accurate for people who run 70+ miles a week. If you aren't running that much, then the calculator will tell you that you are capable of a much faster marathon than you can actually run. If you plug in your fastest 5K or 10K, or even half marathon, chances are that your marathon equivalent is faster than you can actually run. In my case, my 10K, half marathon, and marathon PRs are all equivalent. (All set within 4 months of each other). 49:23, 1:50:43, and 3:51:49. Actually, I should be able to run a slightly faster half marathon based on my full marathon time!
What this all means for me is that a high mileage program won't necessarily help me run a faster marathon. I definitely want to keep my weekly mileage above 45 for the bulk of my training, so I am not saying that a low mileage program is in the cards. But sacrificing speed work for the sake of increasing mileage doesn't make sense in my case. I am fairly confident that if I could run a 47:00 10K, then I could get my 3:40 BQ.
I found a program that has slightly lower mileage than my previous program, and I have merged the two together and created my own plan. I will be doing speedwork at least once a week, and my long runs will sometimes have "fast finishes" where I finish the run at tempo pace for the last 15 minutes. This new program also incorporate Marathon Pace running, whereas the former program rarely had me running at marathon pace. It was usually slower than Marathon Pace, and occassionally faster. Here is a sample workout that I completed yesterday.
1 mile warmup: 9:50 pace
2 miles at Marathon Pace*: 8:32 average
4 miles Tempo: 8:06 average
2 miles at Marathon Pace: 8:28 average
1 mile cooldown: 9:45 pace.
10 miles total, with 8 miles of speedwork that averaged 8:18.
*I realize that my marathon goal pace is 8:24 to BQ, but since I am not at that fitness level yet, I am making "marathon pace" slightly slower.
I've learned that what works for most people in marathon training won't necessarily work for me. Every runner has unique training needs due to genetics and natural strengths and weaknesses. My new plan will have higher mileage than what I've done in the past, although not as high as I was running over the summer. I also think I can remain injury free by keeping the speedwork at the appropriate paces, stretching and continuing with my core strengthening. Also by rotating two different types of shoes as well as both treadmill and asphalt. Just 12 weeks to go until Rock 'N Roll Arizona!