Nutrition creates margins.
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Given the intensity with which Demong monitors every aspect of his training program, it should come as no surprise that he also puts a premium on what he puts in his body. "Honestly, having good nutrition, not only what you eat and when, but also just daily regimens, such as taking vitamins on a daily basis, those kinds of little things really add up into that last percentage," he says. 

In addition to multivitamins, Demong is mindful of the sorts of minerals and vitamins that can counteract the grind of training, and he credits this attention to detail as a deciding factor at his level of competition. "There are specific products that are important to my ability to do the work, recover from the work, and then do more work," he says. "And even on race day, there's things like magnesium, calcium, and zinc that people take for granted because they get it out of their food. Even at an amateur level, a percentage point is a huge margin. In a marathon, it might be 15 minutes, and in the Olympics, it's probably what separates the top 20."