Research appears to indicate that at times of psychological and/or emotional hardship, some habitual exercisers engage in such activity as a form of escape. The reliance on exercise as a means of coping with adversity has the potential become obsessive as well as compulsive. Associated with increased tolerance, over-exercising may lead to physical injuries, and (in extreme cases) irreversible health consequences, and mortality. Over-exercising to the point where a person loses control over the exercise routine has been termed ‘exercise addiction’ or ‘exercise dependence’. Due to the multidisciplinary nature of the literature regarding problematic exercise, different screening instruments have been formulated to assess the problem. In a 2013 issue of the journal Psychology of Sport and Exercise, I and a team of Hungarian researchers published the first ever national study of exercise addiction, and compared two different screening instruments (i.e., the Exercise Addiction Inventory [EAI] and the Exercise Dependence Scale [EDS]).
We made the assumption that these two instruments attempt to assess the same phenomenon. We also published a comprehensive review examining the literature on problematic exercise in a 2012 issue of Substance Use and Misuse and came to the conclusion that the most appropriate term to use is ‘exercise addiction’ because it incorporates both ‘dependence’ and ‘compulsion’. However, most researchers in the field use the terms ‘exercise addiction’, ‘exercise dependence’ and ‘compulsive exercise’ to mean the same thing.
These six core components of addictive behaviour that I outlined in my very first blog served the theoretical foundation for the Exercise Addiction Inventory (EAI). The EAI is a short, psychometrically validated questionnaire that comprises only six statements, each corresponding to one of the symptoms in the ‘components’ model of addiction. However, the cut-off points for exercise addiction were never tested psychometrically. The Exercise Dependence Scale (EDS) was based on the Diagnostic and Statistical Manual of Mental Disorder-IV criteria for substance dependence. The higher the score, the higher is the risk for addiction.
The EAI and the EDS are perhaps the most recent and most widely used screening tools in the research area of exercise addiction, primarily because of their superior psychometric properties in contrast to other instruments, and secondarily because of their theoretical underpinning. However, until our recently published study, these two tools had never been used in a nationally representative study. We assessed exercise addiction within the framework of the National Survey on Addiction Problems in Hungary (NSAPH).
The final sample comprised 2,170 people, stratified according to geographical location, degree of urbanization, and age. Those in this sample who engaged in regular exercise at least on a weekly basis (17.5%) were invited to complete the EAI and the EDS and comprised 474 participants (270 males and 204 females). In line with our assumptions, there was a high correlation between the two exercise addiction/dependence measures. On the basis of results we obtained, we reported that 0.3-0.5% of population is involved in addictive exercise (and equates to 1.9% to 3.2% of weekly regular exercisers).
As mentioned above, our study is the first national study ever to assess the prevalence of exercise addiction in a representative national sample and therefore there are no studies to compare our national findings of the study to. Our study provides primary benchmark data that subsequent national studies will need to be compared to. It is also the first ever study to compare the psychometric properties of (arguably) the two most widely used screening instruments that assess exercise dependence/addiction.
Based on the results of our study, it appears that both of the tools we examined (i.e., EAI and EDS) can reliably be applied in the future for both scientific research in the exercise addiction field, and as a screening instrument in non-research settings. For instance, the short, 6-item EAI could be used as a screening instrument in empirical surveys as a way of combating questionnaire fatigue. It could also be used as a ‘quick and easy’ tool that can be used by health practitioners (such as GPs with their patients) in screening for exercise addiction. The EDS also appears to be suitable for acquiring a more detailed and greater empirical insight to the problem in future studies.
However, there were also a number of limitations to our study. Owing to the sampling method, it was financially impractical to use observational data on physical activity and/or face-to-face clinical interviewing, and therefore we had to base our analysis solely on the basis of self-reports. Self-report data is also prone to the weaknesses of survey methodologies more generally including factors such as recall bias and social desirability. Another limitation was the cross-sectional nature of the dataset, therefore the causality inferences are limited, although further research may identify trends in exercise behaviours and provide models to determine the changes in exercise addiction. Another important question is the generalizability of these results to other countries. However, this question cannot be answered in a reliable way. Though the prevalence of regular exercise is lower in Hungary than in most of the other countries of the European Union, this result, in and of itself, does not necessarily mean that prevalence of excessive exercise is lower as well. It is also possible that though the prevalence of regular exercise is lower than in other countries, prevalence of exercise addiction among the exercisers is higher.
Our results indicate that while optimal regular exercising is a key component of preserving and improving physical and mental health, in case of a small proportion of the population, excessive exercise can generate significant problems. Both the EDS and EAI are adequate screening solutions to assessing exercise dependence/addiction within target populations. While the seven-factor EDS might give a more complex picture on the problem, the short, 6-item EAI has the added advantage of providing anyone who uses the instrument with an estimation of problems with exercise very quickly. Nevertheless, clinical validation of these assessment tools needs to be further targeted and scrutinized by future research.
Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK
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