Abstract: The purpose of our study was to study the prevalence of exercise dependence (EXD) among college students and to investigate the role of EXD and gender on exercise behavior and eating disorders. Excessive exercise can become an addiction known as exercise dependence. In our population of 517 college students, 3.3% were at risk for EXD and 8% were at risk for an eating disorder. We used Path analysis the simplest case of Structural Equation Modeling (SEM) to investigate the role of EXD and exercise behavior on eating disorders. We observed a small direct effect from gender to eating disorders. In females we observed significant direct effect between exercise behavior (r = −0.17, p = 0.009) and EXD (r = 0.34, p < 0.001) on eating pathology. We also observed an indirect effect of exercise behavior on eating pathology (r = 0.16) through EXD (r = 0.48, r2 = 0.23, p < 0.001). In females the total variance of eating pathology explained by the SEM model was 9%. In males we observed a direct effect between EXD (r = 0.23, p < 0.001) on eating pathology. We also observed indirect effect of exercise behavior on eating pathology (r = 0.11) through EXD (r = 0.49, r2 = 0.24, p < 0.001). In males the total variance of eating pathology explained by the SEM model was 5%.
Alex’s Notes: I used to believe that I had an exercise addiction. However, it turns out that exercise dependence (EXD) occurs when a person is obsessed with exercise to the point of withdrawal symptoms upon cessation and interference with life. Since I don’t have either of those, I suppose I just love to be active. Nonetheless, EXD has not been officially classified as a mental health disorder on its own. This is primary EXD whereby the person continuously exercises for the pure psychological gratification they get. Secondary EXD is when exercise becomes a means to an end, such as in some eating disorders like Anorexia Nervosa.
So why am I bringing all this up? Because these types of mental health conditions are no joke and can seriously impair quality of life outside of the medical complications they lead to. It is well known that gender plays a central role in eating pathology, although more recent survey research suggests that the female preponderance is diminishing. Moreover, often eating disorders often begin during adolescence with the greatest frequency being in groups concerned with weight management, such as dancers, gymnasts, figure skaters, models, and wrestlers. To further our understanding of EXD, this cross-sectional observational study surveyed various undergraduate and graduate students from the campus of Andrews University, Minnesota to elucidate
- The prevalence of EXD,
- The role of EXD and exercise behavior on eating disorders, and
- The role of gender on eating disorders
The questionnaires completed by the 517 men and women (on average, 20-years old) included 14 demographic and exercise behavior questions, a 31-item Food Frequency Questionnaire (FFQ; determine who was vegetarian), the Exercise Dependency Scale Test (EDS-21; determine substance dependence), and the Eating Attitudes Test (EAT-26; determine eating disorder prevalence). While it is unfortunate that Andrews University is a Seventh-day Adventist institution, which greatly limits the generalizability to other populations, the study population ethnicity and class standing were quite diverse.
Sadly, 3.3% of the students were characterized as at-risk for EXD, with the prevalence of at-risk for an eating disorder being 8%. It is worth noting that the estimated international prevalence of anorexia nervosa, bulimia nervosa, and binge eating disorder was only 3.24%. In the current study, 10% of participants admitted binging, 2.9% admitted vomiting, 3.7% admitted the use of laxatives, diet pills or diuretics, and 2.1% admitted being treated for an eating disorder in the last six months. Regarding EXD, the at-risk students were mostly male and scored significantly higher on the EDS-21 and EAT-26 tests (greater risk of substance dependence and disordered eating, respectively), and their favorite form of exercise was running and walking. In fact, they spent an average of 14.2 hours per week engaged in some form of exercise, with the average weekly METS being 84.1. This is technically the equivalent of running at an 8mph pace for two hours every day.
Despite this, EXD did not mediate the relationship between exercise behavior and eating pathology, with only (and I use this term lightly) 23% of the EXD at-risk individuals also being at-risk for an eating disorder. However, this relationship changed when METS/week was included as the mediating variable between EXD and eating pathology. That is, overall there was a negative direct effect of METS/week on eating pathology, suggesting that exercise may be protective against developing an eating disorder, but when the person also shows signs of exercise dependence this trend reverses with increasing METS indirectly increasing eating pathology. When stratified for gender, both these effects were found in females, but only the indirect effect was present in males.
Finally, for the third study goal, there was indeed a small direct effect of gender on eating pathology.
This one is hard to pin down. The limitations of the study make it hard to generalize the information (only college students of a single religious practice), and the relationships between EXD and eating pathology were weak at best. Honestly, I am satisfied knowing that this at least brought more awareness to the various mental health conditions that plague our world.