Current studies show an increase in the risk of eating disorders in runners. Since it is known that abusive exercise can be both a cause and a consequence of such developments, the main objective of the present study was to examine the risk and possible relationships between negative running addiction (NRA), as measured by the reduced and validated SAS-40 scale, and the tendency to be a compulsive eater (measured by YFAS 2.0), anorexia nervosa (AN), and/or bulimia nervosa (BN) (measured by EAT-40). This study highlights the novelty of researching the level of influence of NRA on each defined eating disorder. Method: A total of 167 Spanish-speaking federated runners in cross-country and track running (42% women and 58% men), with an average age of 24 years and an average BMI of 21 kg/m2, responded to an online questionnaire that asked about sociodemographic data and the Spanish versions of the SAS-40, YFAS 2, YFAS 3, and YFAS 4. Through a quantitative methodology using logistic regressions—the coefficient of determination and Pearson’s correlation coefficient—we created a sample analysis that related the significant items of the DSM-V to the results of the questionnaires administered, as well as their relationship with the practice of the sport in question and various variables of the environment. Results: The rates of CE, AN, and BN were 65, 11.4, and 16.2%, respectively. The tendency towards CE increased with a lower weight (r = 0.156, p < 0.05), not having been overweight in childhood (r = 0.151, p < 0.05), and being a long-distance runner (r = 0.123 p < 0.05). The risk of AN increased with the absence of menstruation for more than 3 months (r = 0.271 p < 0.01), having suffered from childhood obesity (r = 0.213 p < 0.05), and being underweight (r = 0.064 p < 0.05). The risk of BN increased with having suffered from childhood obesity (r = 0.194 p < 0.05), having a higher weight (r = 0.140, p < 0.05), and practicing athletics, especially the relay modality (r = 0.044 p < 0.05). Conclusions: A considerable number of runners are at risk of suffering from some type of eating disorder. A significant relationship was observed between long-distance runners and the risk of eating disorders (AN, BN, and CE), and the association is stronger for CE than for AN and BN. Lastly, childhood experiences (such as being obese/a healthy weight) were notorious for increasing the risk of eating disorders. Further studies are needed to research each particular parameter and the relationships between the possible levels of dependence on exercise. Level of evidence: Level III, cohort analytic study.