Exercise addiction is characterized by increasing exercise amounts, withdrawal symptoms and lack of control. Eating disorders and exercise addiction often appear together, but only eating disorders are recognized as diagnoses. However, exercise addiction can exist independently from eating disorders and can be as harmful as any other addictive behavior.

The Exercise Addiction Inventory (EAI) is useful to identify exercise addiction symptoms in adults and prevalence rates of 3–10% have been found. But a scale for adolescents does not yet exist even though behavioral addictions seem to be more prevalent among young people.

To develop an instrument for identification of exercise addiction in adolescents and to estimate the prevalence and negative consequences.

We developed a Youth version of the EAI and screened 383 adolescents in sport settings and 69 patients from an eating disorder department (age range 11–20 years).

The psychometric properties of the scale were good (Cronbachs alpha 0.71). The prevalence of exercise addiction was 5.5% in adolescents in sport settings and 21.2% in eating disorder patients. We found a positive linear relationship between EAI-score and “high weekly exercise amounts” (r = 0.4, P = 0.00), “the tendency to exercise in spite of injury” (r = 0.4, P = 0.00), “feelings of guilt when not exercising” (r = 0.5, P = 0.00), “reduced sport performance related to overtraining” (r = 0.2, P = 0.00), and “food dominating life” (r = 0.2, P = 0.00).

On basis of this study, we recommend the EAI-Y for identification of exercise addiction in adolescents. Early identification is important since it can prevent excessive and obsessive exercise, injuries, reduced sport performance and eating disorder pathology.

The authors have not supplied their declaration of competing interest.