@edgarblythe,
You are correct, Edgar. I'm sorry,
Roger, I hadn't seen your early mention of that biking reference.
However, please forgive me now for putting to fine a point on this. I thought the subject at hand was the effort it takes (and the likelihood) of that (or any serious runner) RUNNING 20 miles. A recreational bike ride of 12 mph off road in the woods is not even close to the effort of running 20 miles. Someone in average shape can bike 12 mph for an hour. Yes, I agree that you can lose track of how many miles you have transpired.
However, more importantly..Roger...please understand I didn't mean to offend you or put you off. I just never recalled your earlier comment.