Every year, roughly 2 million people participate in marathons and half marathons in the United States, and, no matter what level they are, every one of these runners has likely hit"The Wall,” running out of muscle fuel in the final miles and slowing down precipitously. This setback and other common running disappointments are nutritional (or metabolic) in nature. In The New Rules , renowned fitness journalist and training coach Matt Fitzgerald cuts through the myths,distilling the most up-to-date science to help runners overcome the universally experienced nutritional barriers that prevent success in the marathon and half marathon.From basic tenets of training to nutrition guidelines, The New Rules is the first resource for runners to fully integrate nutrition with training for a complete and systematic preraceplan. Fitzgerald's powerful and easy-to-use tools will enable runners of all levels to attain their ideal racing weight, calculate their precise daily energy needs, and formulate a custom nutrition plan.