Thank you Mark. It was kind of you to honor my request. And to do so without question, makes the act even more gracious.
So why did I make this request?
The fastest that I can run a 220 is 36 seconds. Mark's mile time is so much faster than mine, I wanted to do some kind of easy sanity check to try and get some insight into this. What Mark's 220 time tells me is that the difference in our mile times is more than just endurance and strength. Speed plays a role also. Mark is at least a full 3 seconds faster than I am for 220. A reasonable implication of this is that he can expected to be a minimum of 24 seconds faster for a mile.
Clearly I've got my work cut out for me.