Salary

Average Salary: $31,720

Expected Lifetime Earnings: $1,324,247


You may be thinking, with all this time spent helping other people improve their bodies, eventually you'll be one of the superstars yourself, conducting classes in the fitness center you had built inside your mansion and relaxing in your Olympic-size swimming pool every evening. It's a fun dream, but not really a realistic one (sorry). On average, fitness instructors make $32,000 per year, or around fifteen dollars per hour (source). 

The money's even worse if you're just starting out or only doing it part-time―a heart-racingly low annual salary of $17,000, or what the U.S. government calls "The Poverty Line." Your place of work may offer health care and benefits, or it may not. But at least you get to use their pool at no charge (unless there isn't one).

So are you destined to live a life in the streets, coming out of the cold to warm up the people who can afford a gym membership (and also to occasionally shower)? Relax, there are a great many ways to boost your income. First and foremost, don't be a part-timer: If you're going into fitness as a career, try to fit in at least forty hours a week leading classes, working gym rotations, and even freelancing yourself out for private sessions.

Certifications in fields like yoga, Pilates, muscle conditioning, aerobics, and dozens of others will help you put a premium on your knowledge―and your gym may even pay you for it. Getting a bachelor's or master's is great too, especially for those who want to specialize in therapy, kids, elder fitness, or making more cash.

 
You need to know how to market. (Source)

Finally, it's difficult to get promoted if you don't have a reputation, so make sure you're consistently working your skills to become the best instructor you can be. Maybe someday you'll be running the joint (and making close to $80,000 to do it).

That being said, there are some incredibly wealthy fitness instructors out there. If you're so into fitness that you can create an entire hundred-thousand-follower fad based around the happy dance you do in front of your mirror, then you definitely have a shot at the life of a rock star.