There is no medical test to determine exercise addiction. People who over-exercise will continue to work out even if they're hurt or sick. Those who jog or exercise outdoors will ignore storm warnings and bad weather. Others will neglect their family and friends, isolating themselves solely to exercise. Control may be a motivating factor in exercise addiction, he says.
Exercise is something that one can control.
You can control the time, you can control how much you do, you can actually measure distance, time and weight. I think control is a big issue in exercise addiction. Over-exercising also can be related to eating disorders, such as anorexia nervosa, and depression. The greatest physical harm of over-exercising is that it creates fatigue and wears down the body's immune system. You're just more susceptible to infection.