Susan has worked with a few adventure racers and if you haven't watched the show yet one of the aspects they didn't spend a lot of time on was nutrition. That said the part they did it was very clear the role that carbs played. 

Other topics covered:

Why adventure racers need more muscle and fat on their bodies for the race.

The mental part you NEED to complete a race like that.

Towards the end we talk about how quickly the new mom recovered from her pregnancy to participate in the race.