Qualifications
There's no standard, overall qualification for the professional fitness instructor. Every facility, be it gymnasium, hospital, or office stretching corner, has its own specific requirements for fitness personnel. If you're just looking to lead classes on a part-time basis, you won't really need anything more than a high school diploma and a willingness to go through training.
However, you're reading this, so that means you might want to be more than just a part-timer. For those of you passionate about fitness, college degrees and/or certifications are definitely the way to go. As we stated in the Salary section, your maximum income potential (or MIP, for people who don't like big words) relies on either how specialized or how varied your abilities are.
Having a degree in exercise science or certifications in yoga, Pilates, and core will give you more opportunities to excel as a fitness instructor. Of course, paying back student loans on a fitness instructor's budget isn't the easiest thing in the world, so you have to make sure your learning plan is tight and specific.
It's also a pretty good idea to be in shape. You're going to be moving/stretching/lifting/holding/expanding multiple times a day, every day. You probably shouldn't be screaming in pain while you do it; your class will have a difficult time focusing.
Also, that's in shape, not built like a Greek statue. You don't need rock-hard abs or bleach-blonde hair or to look like a contestant on America's Next Top Model. Fitness instructors come in all shapes and sizes; what is important is that they listen, they lead, and they help clients create results.