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.