The recent addition of a behavioral addictions category in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) has provided a framework to examine when behaviors progress from normal to pathologically excessive. Several behaviors that are either typically harmless (e.g., gambling, shopping) or even healthy (e.g., alcohol consumption, sex) when performed in moderation have been identified as having addictive potential. Exercise is one such behavior that may be viewed as an addiction. However, the literature is confused by several terms such as compulsion, addiction, and dependence that all may refer to similar, if not the same, pathological patterns of problematic exercise. This chapter will first review the various terms that are widely used and provide a clear distinction among exercise addiction, dependence, and compulsion. Next, we will review assessment measures that are commonly used in research and in clinical practice to screen for problematic exercise patterns. Finally, we will discuss the emerging literature that examines the co-occurrence of problematic exercise and eating pathology, substance use disorders, and other behavioral addictions.