Defining “exercise addiction” – recruitment and measurement strategies for an innovative study

Background While numerous cross sectional studies have addressed the topic of a possible “exercise addiction”, excessive exercise is not yet a form of behavioral addiction defined in the DSM V. There is debate about whether these patterns of exercise occur in isolation, or whether they always accompany other disorders; furthermore, there is virtually no evidence on the biological substrates of this condition. It must be noted that exercise is frequently a socially lauded behavior. Individuals who exercise excessively may therefore not have absorbed critical personal or societal feedback about their behavior, and be less conscious of its negative impact. This can pose a particular challenge in recruiting these individuals for studies which aim to provide insight into the nature of this disorder.

Methods The study protocol presented here involves three phases: first, active individuals will be recruited and screened with self-report questionnaires for a number of psychiatric disorders. Those who exceed the cut-off on the Exercise Dependence Scale will undergo intense clinical interviewing, in order to establish the nature of their exercise habits, and whether they suffer from other psychiatric disorders. These individuals will also undergo FMRI scanning, in order to establish whether neural substrates of excessive exercising can be identified; these images will be compared with those of inactive controls and substance-dependent individuals.

Results We present initial results of the first phase of the study, details about the recruitment strategy, and hypothesized areas of relevance for the neuroimaging phase of the study.

Discussion The initial findings presented here are a first step towards a definitive categorization of excessive exercise as a behavioral addiction or symptom cluster.