Exercise Dependence, Eating Disorder Symptoms and Biomarkers of Relative Energy Deficiency among Male Endurance Athletes

Abstract

Exercise dependence (ED) is characterized by a craving for physical training, uncontrollable excessive exercise behavior with inability to reduce exercise amounts, and potential harmful consequences, such as injuries, impaired social relations and depression. The condition is often associated with eating disorder pathology and perfectionism among women. Whether an association between ED and eating disorder symptoms among male endurance athletes exists, is less known. PURPOSE: The aim of this study was to explore possible associations between ED, eating disorder symptoms, and biomarkers of Relative Energy Deficiency in Sports (RED-S) among male athletes. METHODS: Fifty-three healthy well-trained male cyclists, triathletes, and long-distance runners recruited from regional competitive sports clubs were included in this cross-sectional study. The protocol comprised the Exercise Dependence Scale (EDS) consisting of 7 sub-scales, the Eating Disorder Examination Questionnaire (EDE-Q), measurements of body-composition, resting metabolic rate, energy intake and -expenditure, and blood analysis of hormones and glucose. RESULTS: Subjects with higher EDS score displayed a more negative energy balance compared to subjects with lower EDS score (p < 0.01). EDS total score was positively correlated with EDE-Q global score (r = 0.41, p < 0.05) and the subscale score for Restraint eating (r = 0.34, p < 0.05) and Weight concern (r = 0.35, p < 0.05). EDS total score and the subscales Lack of control and Tolerance were positively correlated with cortisol (r = 0.38, p < 0.01, r = 0.39, p < 0.01, and r = 0.29, p < 0.05, respectively). The EDS subscales Withdrawal and Tolerance were negatively correlated with fasting blood glucose (r = -0.31 and r = -0.32, p < 0.05, respectively), while Intention effect was negatively correlated with testosterone:cortisol ratio (r = -0.29, p < 0.05) and positively correlated with cortisol:insulin ratio (r = 0.33, p < 0.05). CONCLUSION: In this sample of healthy male athletes we found positive associations between higher EDS scores, eating disorder symptoms and biomarkers of RED-S, such as a more pronounced negative energy balance and higher cortisol levels. More studies are needed to elucidate ED as a possible contributor to the syndrome of RED-S.