Purpose: Exercising can promote good health. However, excessive exercising may have downsides. This study examined the association between exercise addiction and eating disorders and whether the identified association was mediated by psychological distress, insomnia (including sleep quality), and body image concern.

Methods: A total of 2088 adolescents (mean age of 15.3 years) participated in this cross-sectional study by questions assessing exercise addiction, eating disorders, psychological distress, insomnia, sleep quality, and body image concern.

Results: There were significantly positive relationships between the variables (r=0.12-0.54, p<0.01) with effect sizes from small to large. The four potential mediators (ie, insomnia, sleep quality, psychological distress, and body image concern), individually and in total, significantly mediated the association between exercise addiction and eating disorders.

Conclusion: The findings suggest that exercise addiction in adolescents may influence eating disorders through multiple pathways, such as insomnia, psychological distress, and body image concerns. Future research should examine these relationships longitudinally and use gathered information to inform intervention development. Clinicians and healthcare workers are encouraged to assess exercise addiction when treating individuals with eating disorders.