Distance runners spend many hours training assiduously for competition, yet on race day they can often make mistakes that sabotage their performance. This article addresses five common race-day mistakes: (1) failure to bring proper equipment to the race; (2) failure to eat an appropriate race-day meal; (3) failure to hydrate properly; (4) failure to warm up properly; and (5) failure to maintain a proper pace. It is directed particularly to those who coach high school and college distance runners for five-, eight-, and 10-kilometer races. Underlying the discussion of race-day mistakes are the following assumptions about the health status of a runner on race day: (1) The volume and intensity of the runner's training program is physiologically sound and in keeping with optimum performance on race day; (2) The nutritional practices of the distance runner are sound, and the runner does not have eating disorders or nutritional deficiencies; and (3) The distance runner does not have any injuries or illnesses at the time of competition. Being knowledgeable about race-day mistakes allows coachesand athletes to work on minimizing or eliminating them altogether. Knowledge is power, and it will prove itself by an athlete's performance when it counts the most--in competition on the day of the race.