Eddie Merckx used to eat stake for breakfast on the morning of a big ride cf A sunday in Hell.

A tradition in the tour de France was that the domestiques steal wine form local bars and cafe for the team favorites. Now I know you will not have a domestique and I don't condone stealing but reasonable wine is cheap in France and as we all know drinking makes your stronger and faster as well more attractive to the opposite sex, funnier e.t.c So I recommend wine, red preferably.