Endurance runners exhibit an elevated prevalence of low bone mass and characteristics consistent with undernourishment.This quasi-experimental, pretest-posttest design study evaluated the efficacy of a 4-week nutrition education curriculum to optimize nutrition knowledge, self-efficacy, and the intake of nutrient-rich carbohydrate foods.Forty-eight adolescent endurance runners, age 15.7 ± 1.2 y, from two high schools in Southern California were recruited to complete four, weekly lessons addressing the quantity, quality, and timing of carbohydrate intake. Differences in pre- compared to post-intervention nutrition knowledge and self-efficacy to consume nutrient-rich carbohydrate foods were evaluated using paired samplesThe percent of nutrition knowledge questions answered correctly increased after Lessons 1 and 2 (59.0% ± 20.0% pre- vs. 81.9% ± 22.8% post-Lesson 1; 44.7% ± 13.7% pre- vs. 74.5% ± 17.4% post-Lesson 2