Careers in fitness and health span across many fields, ranging from retail to medicine. Personal trainers, athletic trainers, exercise instructors, massage therapists, nutritionists, and wellness coordinators are some of the most common. If you have a background in fitness, you may decide to open or manage a spa, gym, health club, or sports and fitness equipment store. Many healthcare careers also center around physical fitness, including physical therapists, medical assistants, sports physicians, and sports psychologists. Educators who teach biology, health, and related classes can also benefit from learning as much as possible about fitness.