My body took control today. Mind told body this morning that they were going to run 20 miles. Body reminded mind that they had just gotten home from the hospital, that they had been awake for 24 hours, and that they needed to sleep for awhile. Mind relented, assuming that body would be ready to wake in 5 or 6 hours, as is the norm for us.
13 hours of wow-I-didn't-know-the-world-existed sleep later, mind and body awoke and together realized they couldn't fit 20 miles in this afternoon before it was time to once again save lives at the hospital.
So they agreed to postpone 20 miles to tomorrow.