Compulsive exercise (also called obligatory exercise and anorexia athletica) is best defined by an exercise addict's frame of mind: He or she no longer chooses to exercise but feels compelled to do so and struggles with guilt and anxiety if he or she doesn't work out. Injury, illness, an outing with friends, bad weather - none of these will deter those who compulsively exercise. In a sense, exercising takes over a compulsive exerciser's life because he or she plans life around it. Of course, it's nearly impossible to draw a clear line dividing a healthy amount of exercise from too much. The government's 2005 dietary guidelines, published by the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services (HHS), recommend at least 60 minutes of physical activity for kids and teens on most - if not all - days of the week. Experts say that repeatedly exercising beyond the requirements for good health is an indicator of compulsive behavior, but because different amounts of exercise are appropriate for different people, this definition covers a range of activity levels. However, several workouts a day, every day, is overdoing it for almost anyone. Much like with eating disorders, many people who engage in compulsive exercise do so to feel more in control of their lives, and the majority of them are female. They often define their self-worth through their athletic performance and try to deal with emotions like anger or depression by pushing their bodies to the limit. In sticking to a rigorous workout schedule, they seek a sense of power to help them cope with low self-esteem. Although compulsive exercising doesn't have to accompany an eating disorder, the two often go hand in hand. In anorexia nervosa, the excessive workouts usually begin as a means to control weight and become more and more extreme. As the person's rate of activity increases, the amount he or she eats may also decrease. A person with bulimia may also use

From: http://kidshealth.org/parent/emotions/behavior
/compulsive_exercise.html