Good nutrition--both before the race and during--is critical if you hope to excel in any running race. When you run long distances, your energy requirements increase. In an article on endurance exercise in The Physician and Sportsmedicine, Walter R. Frontera, M.D. and Richard P. Adams, Ph.D., comment, "During sustained exercise such as marathon running, total body energy requirements increase 10 to 20 times above resting values." Runners need to eat more of the proper foods to fuel their muscles. They also need to drink more, particularly in warm weather.

At a sports nutrition seminar in connection with the 1992 US Olympic Marathon Trials in Columbus, Ohio, Linda Houtkooper, Ph.D. a registered dietitian at the University of Arizona, made clear that endurance athletes in particular should get most of their calories from carbohydrates.