Exercise is generally seen as a virtue; therefore, you may wonder how it could possibly be bad for you. For most people, exercise does confer significant health and mental health benefits. However, for those with eating disorders, excessive exercise is a common symptom and can play a role in the development and maintenance of the disorder.1 Our culture’s celebration of exercise makes it so that excessive exercise is often not recognized or taken as seriously as it should. Visit discovermagazine.com to learn more about dietary supplements.
This article will describe excessive exercise as it has been studied by eating disorder researchers, and then review how excessive exercise manifests itself in various eating disorders, the risks of overexercising, and what to do if you think you (or a loved one) are engaging in too much exercise.
Whereas most people would understand self-induced vomiting to be a negative eating disorder behavior, they would generally not think the same of exercise. Those who exercise excessively are often praised for their motivation and self-discipline. But taken to an extreme, this behavior can have serious consequences. Check out these Resurge reviews.
In one of the largest studies on excessive exercise in eating disorders, excessive exercise was defined as any of the following:
- Exercise that interfered with important activities
- Exercise that exceeded three hours per day and caused distress if the individual were unable to exercise
- Frequent exercise at inappropriate times and places and little or no attempt to suppress the behavior
- Exercising despite more serious injury, illness or medical complication
Link to Eating Disorders
Excessive or driven exercise is a common component of different types of eating disorders. It may be found among patients with anorexia nervosa, bulimia nervosa, and muscle dysmorphia, as well as other specified feeding and eating disorder (OSFED) and subclinical presentations. In the case of restrictive eating disorders, including anorexia, there is even some evidence that increased exercise may be a fundamental biological reaction.2
Activity-Based Anorexia in Rats. Animal studies have demonstrated that eating disorders can give rise to excessive exercise behavior, by inducing what is called “Activity-Based Anorexia” in rats. When researchers restrict rats’ food intake while giving them unlimited access to a wheel, many of the rats become hyperactive and run more than they did prior to the food-restriction. Paradoxically, these rats opt to continue running rather than eat during the short intervals of time food is made available to them. If allowed, they will literally run themselves to death.3
These rats display the puzzling behavior of self-starvation exhibited in anorexia nervosa. One would expect that rats (and humans) who are starving would become less, rather than more, active. Yet in young children who develop anorexia nervosa, restricted intake is usually accompanied by increased activity. Youngsters with anorexia often present as hyperactive—they won’t sit still, they fidget, and they often run around aimlessly. They do not express a conscious attempt to burn calories the way older adolescents and adults do. Thus, excessive activity or exercise is postulated to be a more basic drive that gets turned on by the energy imbalance of restricted intake.
Exercise in Anorexia Nervosa. Hyperactivity is a common, intriguing, and well-documented symptom of anorexia nervosa,4 noted as early as 1873 by the French physician Ernest-Charles Lasègue, one of the earliest writers about the disorder. Lasègue observed that patients with anorexia exhibited high levels of activity seemingly incompatible with their impoverished nutrition:
Another ascertained fact is, that so far from muscular power being diminished, this abstinence tends to increase the aptitude for movement. The patient feels more light and active, rides on horseback [the French text also mentions: ‘long walking-tours’], receives and pays visits, and is able to pursue a fatiguing life in the world without perceiving the lassitudes he would at other times have complained of. (Lasègue, 1873, p.266)
In one study, 37 percent to 54 percent of patients with anorexia nervosa (depending on subtype) engaged in excessive exercise. Patients may underreport the amount of time that they engage in physical activity, making it hard for caregivers and treatment professionals to fully assess.
Exercise in anorexia nervosa is commonly described by patients as driven or compulsive. Physical signs of fatigue are ignored as patients continue to train despite being physically ill and low energy.
One patient in a study about exercise reported:
“Before I attended treatment, I only sat down during meal times, or else I felt I did not deserve to sit still. I was incredibly restless, so it was difficult to relax…I feel like I am being compelled to exercise…”5
Excessive exercise in anorexia nervosa is associated with younger age and higher rates of anxious/obsessional and perfectionistic traits.
Exercise in Bulimia Nervosa. Excessive exercise has been included in the diagnostic criteria for bulimia nervosa since the publication of DSM-III-R in 1987. The current diagnostic criteria (DSM-5) for bulimia nervosa specify that there is compensatory behavior for binge eating which can include self-induced vomiting, but also intermittent fasting, laxative use, diuretics, and excessive exercise.