Actually, I'm only three-quarters done with the book. The only exception he has mentioned to the rule is "truly elite athletes" (to be defined later), who should eat twice as many FAT calories (all monounsaturated).
He points out that by keeping a protein/carbohydrate balance (and thus insulin/glucagon), fat becomes a much more usable energy source; and while the average marathon runner has *just enough* stored glycogen to finish a marathon, he would have enough stored bodyfat to finish [three or four digits' worth, I don't recall offhand] marathons.
I believe that the point he makes is that marathon runners do not have higher-than-average "glycogen" requirements, but higher-than-average "energy" requirements--and on the diet that he recommends, rather than the standard carbo-load, fat becomes a viable source of said energy.
SPC Jason C. Diederich, MOARNG
FEMAS, Bujinkan Budo Taijutsu, Kali-Silat
www.geocities.com/shaolinninjamarine