Working Class Runner

First, I want to thank reader Goran for contacting me out of the blue and asking about the Marathon Shape tool I had been developing.

While life and circumstances have once again kept me busy (hence yet another extended radio silence from me), I have periodically worked on developing this Marathon Shape tool to help estimate marathon shape. I’m currently training for another marathon myself, so I’ve found use in continuing to refine the tool(-in-progress).

For those who don’t know, the very helpful training dashboard site Runalyze has a metric called Marathon Shape that estimates your ability to race a marathon based on your Estimated VO2max and its records of your prior training.

Your Marathon Shape is shown as a percentage: A 100% marathon shape indicates you can race the marathon to your potential (Runalyze has a race time projection calculator), and lower marathon shape numbers indicate a potentially slower finish, if not a risk that you cannot finish your marathon. Obvious caveats apply: You need to properly train for a marathon (whatever that means to you the end user), and so on.

If nothing else, over time I have found marathon shape remarkably telling in why I’ve fallen short in some marathons but done better in others. There is a direct correlation between my marathon shape and the results I’ve noticed. So have many others who use Runalyze, as indicated by Goran’s interest in where I’m at with this tool I have mentioned working on.

An obvious issue is that while Runalyze is great at showing metrics for all your prior training and racing, it does not really allow you to project future training and show what your metrics will look like afterward. Other than the aforementioned race projection calculator, you have to separately do that on your own off the site.

I’ve always tracked my training separately on a Google Doc, as well as planned future training and racing, and tinkered over the years with building functions that can project those key metrics, like marathon shape, as well as workload ratio. (Training monotony is so complex that I’ve for the time being given up on trying to project that and often just research that separately.)

There was an old Runalyze forum post where the proprietors in answering a reader’s question spelled out the formula for calculating Marathon Shape, but I cannot find it now so perhaps it was deleted. After verifying with my training data that the function was accurate, I made some adjustments (the function measures kilometers so I had to convert to miles) and plugged the function into my Doc. I also had to create a variety of other functions to project my Shape in real time for today while projecting Shape for the future date of my marathons. To this day I still have to constantly adjust functions to make it currently accurate for myself (so don’t expect an end-user-friendly doc that can do the above from me anytime soon).

However, because erasing and re-entering my planned training in my Doc is such a pain, I’ve gradually developed a separate Marathon Shape Estimator workbook to allow me to plug in mileage for different plans and estimate what kind of marathon shape it will leave me in.

And so, here we are.

Admittedly I’ve always had doubts about the Marathon Shape tool being ready for public consumption, and that’s why you hadn’t seen one.

But I have to realize truth in a saying I’ve sworn by often when it comes to crossing a threshold or taking a leap of faith: “You are never truly ready, though truly you are always ready.” In light of Goran reaching out, I think it’s time to share the tool with the public.

Being a practitioner of form over function, I had to make design adjustments to make a Marathon Shape Calculator more generally user friendly. Plus, I realize there’s some limitations you may run up against in using it (currently you will need Microsoft Excel to use it). But, here it is.

The Marathon Shape Calculator (v2025.02.01)

Below, an image of what it should look like, and more info.

Inspired by another tool I use a lot, the Electric Blues Daniels Training Tables document, the Marathon Shape tool allows you to enter your Estimated VO2max, your race date, and (with some admittedly tedious work) all of your prior and planned mileage ahead of the race, up to 26 weeks out (as Runalyze calculates your marathon shape based on all mileage from the past 26 weeks).

You may enter data in any field in yellow.

There are two tabs, one to enter in miles and one to enter in kilometers. As a sample, I pre-entered data in each sheet for a runner who runs 25-26 miles per week (40km per week) that uses the 18 week Hal Higdon Intermediate 1 Marathon training plan to train for a race.

Once you enter all of your prior/planned training volume, the Calculator will produce an estimated marathon shape, plus a summary total of your Long Run values (which counts 1/3 of your Marathon Shape) and total training volume from the prior 26 weeks (the other 2/3).

I did lock the non-yellow cells in the document to avoid you erasing any titles or functions, but the Miles sheet does at the bottom have a password to allow you to unlock and edit the document if you wish (at your own risk, of course). If you think you can improve on this document, absolutely feel free to do so! I am providing it as a(n admittedly long overdue) public service.

As the Laufcampus proprietors of Runalyze have stated many times, the total Long Run score should ideally reach a total of 10.0 points. Readiness to race the marathon may be a concern even at 100% Shape if the total Long Run score is less than 10.0. Conversely, the Long Run score can exceed 10.0 even though your Shape is below 100%, which itself could be a concern. Use this data as you wish.

The result you see on the Calculator may vary from the Marathon Shape you see on Runalyze for a few reasons:

1. On Runalyze your Marathon Shape is calculated as of today. The impact of any long runs on your Shape exponentially decays based on how recently you performed them, up to when they are dropped after 70 days. The Calculator’s result is the Shape you should expect to be in on the morning of your marathon, based on the Estimated VO2max you have entered if all listed training volume is done as entered.
2. Total mileage is calculated equally no matter when during the last 26 weeks it was done, but keep in mind that a run done 182 days ago will no longer count tomorrow, as it will fall outside the 26 week window. Volume you’ve done drops off everyday.
3. Your Estimated VO2max (EVO2max) changes every time you complete a qualifying training run, as each run has a calculated EVO2max of its own, which Runalyze factors into the Estimated VO2max it shows. You can always adjust the EVO2max in the Calculator to revise your projected Marathon Shape.

Also, and this is a separate topic plus it’s own can of worms… but you may notice that if you use a pre-written training plan that, after entering your data, your Marathon Shape may always seem to be low.

Yes. This is correct. The majority of pre-written training plans out there typically leave you at anywhere from 75-85% Marathon Shape, with a Long Run score below 10.0.

Unfortunately, a lot of traditional training plans do not provide many recreational runners with the volume that Laufcampus’ Marathon Shape metrics have determined a runner optimally needs to effectively race a marathon, or at least do so without significant distress. While the Shape metric is based on long-term first-hand research, traditional training plans are usually based solely what the writer believes has worked before, and what they were taught by coaches who have learned the same way.

Again, this is a whole other topic probably too complex and broad for the end of this post. I’ll approach it another time. But, expect most pre-written training plans to leave you at 75-85% Marathon Shape.

You can proceed with that at your own risk, lower your race day expectations, or (provided more than 6 months to train) do an obvious workaround and run higher mileage prior to the training plan (though for many plans that won’t solve the Long Run score problem, since that’s based on the last 10 weeks of training and will only include the pre-written workouts).

You can also change the training plan, though that’s not recommended as these plans are written the way they are for a lot of good physiological reasons. You risk injury or undertraining changing them instead of just training with another plan or with coaching.

I hope this tool is useful for you. Of course, please contact me if there’s questions (I remain busy but I’ll do my best to answer in reasonable time), or any information I should know.