I thing I have noticed in regards to the Marathon Shape calculation is the dramatic swing over a 24 hour period.
For example, yesterday I completed a 14 mile run and my marathon shape was 100%. Today I went to the gym and do an easy 2 mile recovery/warm-up run before doing a core and weight workout. I completed the warm up in 20:00, so I was running at an easy 10 min/mile pace. When I enter this into the software my marathon shape dropped to 45%. My overall fitness stayed the same, so did my effective VO2 Max.
What would cause this dramatic of a drop in the marathon shape? Maybe I don't really understand how it is calculating this score and it is natural for this to occur. I am going into marathon training season so I am curious about this.
Thanks for any insight into this curious behavior.