What training does Ralston do within a 60 hour period that tells him he is ready for his Denali trip?

First he climbs and skies Cathedral. Then he goes out to skin Conundrum Basin and ski that area and continues on with Quandary Peak with a Denali teammate. The next day, he runs a marathon length route right before a eight hour shift of work. In all, he skies, hikes or runs over 50 miles.