Here are some thoughts on the topic based on my research, but please chime in if you have suggestions.
*Beets/Beetroot Juice - Beets have been shown to reduce oxygen uptake requirements during prolonged periods of exercise. They also act as vasodilators and reduce blood pressure, among other benefits. To quote this article:
"Could eating beets/drinking beet juice before daily training help athletes train harder and thereby compete better? Perhaps. Nitrate-rich beets, concentrate beetroot juice â??shotsâ??, and other nitrate-rich foods (spinach, rhubarb, arugula) get converted into nitric oxide, which helps reduce the amount of oxygen needed during constant-work-rate exercise. Hence, for the same oxygen uptake, athletes who consume beet juice â??shotsâ?? might be able to exercise harder. For example, a runner might improve by 5 seconds a mile."
I could see this being a big help as the competition day goes on (I have heard competitions can last over 6 hours, the one I am going to is all day).
*Dark Chocolate - I was surprised to read that dark chocolate might be very beneficial to weightlifters. Aside from having trace minerals and cardiovascular benefits, dark chocolate has a compound called Epicatechin which can improve stamina. This article provides an overview of an interesting study:
*Water - at least 1 gallon, maybe two
*peanuts/PB&J sandwiches - It seems like lost of people pack these, but I am not sure why. I would think that one would get sick to their stomach eating something so sugary/pasty/fatty. I can understand bringing a bag of mixed nuts, as peanuts are very high in calories and nutrients, and contain protein.