By Danielle Keenan-Miller, Ph.D.
Exercise is, undoubtedly, a generally healthy enterprise and many people embark on new exercise routines at this time of year. While most people are striving to meet the Department of Health’s guidelines of 150 minutes of moderate intensity or 75 minutes of vigorous activity per week, some people go far beyond those recommendations. In a world of “insanity” workouts, encouragement of “double” spin classes, and nonstop news articles on the harmful health effects of being sedentary, it’s easy to assume that more is always better when it comes to exercise. However, in too large of a dose, exercise can have negative effects for both body and mind.
How would you know if you or someone around you has crossed the line from healthy exercise into a potentially risky compulsion? How much is too much? As an avid runner myself, I know that people’s ideas of how much exercise is “enough” or “too much” tend to be pretty subjective. An adequate amount of training for a 5K is going to be different than the amount of training you need to run a marathon, which is less still than is needed to train for a triathalon or an ultramarathon.
It turns out that the answer is less about the total amount of time spent exercising and more about the impact that the exercise has on someone’s life. Experts generally think of exercise as problematic when there are signs similar to other kinds of addiction. One important warning sign is withdrawal—difficulty coping, depression, anxiety, or anger when a workout can’t be completed. Similarly, if someone keeps exercising even though they know there is a physical reason not to, like an illness or an injury of some kind, that’s often a tipoff that the relationship to exercise has become unhealthy. Problematic exercise is also likely when exercise gets in the way of important other things in life—time with friends or family, work, or adequate rest. Some, but not all, people with exercise addiction also have an eating disorder. 
One common screening measure used to measure the risk of problematic exercise is the EAI (Exercise Addiction Inventory).  If you’d like to check your own risk, rate each statement below on a scale of 1 (strongly disagree) to 5 (strongly agree):
- Exercise is the most important thing in my life
- Conflicts have arisen between me and my family and/or my partner about the amount of exercise I do
- I use exercise as a way of changing my mood
- Over time, I have increased the amount of exercise I do in a day
- If I have to miss an exercise session, I feel moody and terrible
- If I cut down the amount of exercise I do, and then start again, I always end up exercising as often as I did before.
Research using this measure suggests that total scores of 24 or more are associated with a high risk of exercise addiction, with scores between 13 and 23 suggestive of possible concerns related to dependence on exercise.
There are biochemical and perhaps even genetic causes underlying the development and maintenance of exercise addiction. If you suspect that reducing the compulsiveness of your exercise might require professional support, cognitive-behavioral therapy is the treatment of choice.
 Freimuth, M., Moniz, S., & Kim, S.R. (2011). Clarifying exercise addiction: differential diagnosis, co-occuring disorders, and phases of addiction.
 Berczik, K., Szabo, A., Griffiths, M.D., Kurimay, T., Kun, B., Urban, R., & Demoetrovics, Z. (2012). Exercise addiction: Symptoms , Diagnosis, Epidemiology, and Etiology. Substance Use and Misuse, 47.
 Terry, A.., Szabo, A., & Griffiths, M. (2004). The exercise addiction inventory: a brief screening tool. Addiction Research and Theory, 12, 489-499.
 Weinstein, A. & Weinstein, Y. (2014). Exercise Addiction: Diagnosis, bio-psychological mechanisms and treatment issues. Current Pharmaceutical Design, 20.