Well, is it negatively affecting his life? Is he able to go without doing that activity? You can be at the gym every day, and not be addicted to fitness, or you can be there every day and be strongly addicted to it. The first person would be fine with taking a few day shots off for a vacation, where the second person wouldn’t be able to comfortably do that, or would spend half their vacation at a different gym. Someone who is passionate about fitness will not push through workouts despite injuries. Someone who is addicted to it likely will.