I learned about cycling-related Eddington numbers recently.
They are the largest integer n such that you have ridden at least n kilometers on at least n days (not necessarily consecutively).
I wrote some code to find mine.
With data from 2001 to 2024, my Eddington number is 102.
So, I rode at least 102 kilometers on at least 102 days, and have not ridden at least 103 kilometers on at least 103 days. Apparently, I've ridden at least 103 kilometers on 101 days, so I'll need to do that twice more to get my Eddington number up to 103. Sounds like a nice goal for 2025.
One can also use miles. An amusing thing to note is that you cannot simply convert the Eddington number in kilometers to the Eddington number in miles, since we're counting days.
My Eddington number in miles is 68. 68 miles is about 109 kilometers, so my Eddington number in miles is both larger and smaller than my Eddington number in kilometers.
One can, of course, apply this to running, walking, swimming, or really any other quantifiable activity.
Let me know if you'd like the (simple) code I wrote to calculate these.