Addiction to exercise- a hidden addiction?
It's good to read this article  on a subject that contradicts the mainstream trend in medicine. The authors highlighted research dilemmas of exercise addiction. There are methodological issues in the definition, diagnosis and etiology . Survey methodology indicates that the prevalence of the risk for exercise addiction is about 3% among the exercising population, 10% among high-performance runners.
Neurobiological effects of exercise involve a wide range of interrelated influences on brain structure and functions. Exercise produces different, endogenous neurotransmitters, neuropeptides and neuromodulators (phenethylamines, the opioid β-endorphin, the endocannabinoid anandamide). The result can be euphoria ("runner's high”). Exercise addiction is a state characterized by a compulsive engagement in any form of physical exercise, despite negative consequences, i.e. regardless of physical injury. An addiction includes repeated compulsive behaviors that negatively affect daily living. It may involve the occurrence of severe withdrawal symptoms when the individual is unable to exercise.
Starcevic and Khazaal  showed the complex relationships between behavioral addiction and psychiatric disorders. Associations with depressive and anxiety disorders are strong. Other associations seem relatively specific between exercise addiction and eating disorders, as a secondary symptom of bulimia or anorexia nervosa. Approximately 39-48% of patients suffering from eating disorders are also addicted to excessive exercise. It influences not only the development of eating disorders but also their maintenance. There are reports that over-exercise is a major risk factor for suicidal behavior in patients with eating disorders . DSM -V classified excessive exercise under “behavioral addiction” in which a person’s behavior becomes obsessive, compulsive, and/or causes dysfunction in a person's life . Specifically, the topics of addictions relating to sex, exercise and shopping were discussed , but not included because of insufficient evidence of diagnostic criteria. In my opinion, the important point is to define excessive exercise as an independent entity and to classify it as a clinical disorder. The term “exercise addiction” continues to be debated. Different assessment tools can be used to determine an addiction. There are discrepancies in the interpretation of these diagnostic tools . A refinement of the screening is necessary to improve assessment to identify people affected by or at risk of exercise addiction.
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Competing interests: No competing interests