10. Wellness Instructor
Over a quarter of Americans are obese, which means there's plenty of work to go around in the fitness industry. In fact, employment in the fitness business is expected to increase 29 percent by 2018, according to the Bureau of Labor Statistics.
You don't have to invest in expensive equipment to get started, because you can train your clients at the local gym, the Y, or even in the park, like those bootcamps that are so popular these days. Instead, invest a few hundred dollars in building a website and advertising. You can also put up flyers at local sports and fitness stores.
You should also get certified. A number of national certification programs such as the American Council on Exercise, International Sports Sciences Association, and American Fitness Professionals and Associates provide education and training in the personal fitness trainer field.