I've already determined what I'll do today and tomorrow

Article in NYT about oncologist recovering from testicular cancer Clark Gamblin who ran 7 marathons in 7 days on 7 continents.  

One most days, he started at 4:30 a.m. He listened to Led Zeppelin or AC/DC and devoured audiobooks of memoirs and mysteries. When he thought about his goals all at once - seven marathons in seven days - it felt daunting. But when he broke it down into daily practice, he had a road map to follow.  He is a habitual list maker, often writing down things he already did just to check them off, but he developed another strategy to stick with his plan. He created a seven-day calendar, filled with commitments and training runs, and then revisited it each night, always updating the eight day away. 

"I don't think about what I'm going to do today and tomorrow," he said. "I've already determined that."