Why is it that some fitness professionals earn over $100,000 while others are just scraping by? You might think they know something you don't. Maybe they have better marketing. Maybe they have better systems in place for signing up new personal training clients. Or, maybe they work in a better environment. But if we dissect each of those "maybes," we'll find that although each of them can turn a mediocre trainer into a very profitable one, it's not the deciding factor.

I can say that because over the past 15 years I've seen fitness pros succeed despite terrible odds stacked up against them. I've seen trainers making over $80,000 in a local Worlds Gym in a very poor part of town. I've also seen fitness professionals with little experience making three times as much as seasoned veterans who have every certification under their belt.

These trainers had what I call the ONE thing you can't teach. And, it's this ONE thing that dictates whether you'll end up making it big AND sustaining your success. Because you have to remember, it's one thing to build up a stacked schedule and a whole other thing to keep it that way month after month and year after year.

Napolean Hill in his book, "Think & Grow Rich," referred to this one thing you can't teach as “perseverance.”

However, I feel what he meant by that word was more of an "attitude" that one needs to embody in order to be in the top 5% of their profession and to really be successful. You need to have a confident, stubborn swagger about you and live by this one phrase, "whatever it takes." I refer to it all the time as the "whatever-it-takes attitude."

The greatest sports players in the world will do whatever it takes to be the best. They'll search out coaches, they'll shoot hoops at night in the dark on the playground trying to perfect their jumpshot, or skip going out on Friday night with friends in order to watch some film. And, when those best players in the world begin to get older and they're not as fast or explosive as they use to be they find other ways to still dominate and be the best. They become smarter instead of just relying on skill.

They are willing to do whatever it takes.

Look at Michael Jordan. When he got older and couldn't dunk over everybody at will he decided to beat his opponents in other ways. He came back the next season with a three-point shot in his arsenal...

Now when it comes to personal training you need to have this whatever it takes attitude as well.

The reason I say that is because sometimes you need to build up your marketing, sometimes you'll need to improve your lead generation, and other times you'll need to figure out how to retain your clientele to a greater degree. The education and skills department is different for each trainer, but the one thing that never changes is your attitude towards your success.

As I said earlier, this is something you can't teach.

I can show you how to use offline and online marketing to get new clients, how to set up systems to keep your business organized, and how to maximize your time to get the most done, but what I can't do is change your mindset.

I can't teach you how to be willing to sacrifice giving up the good in your life to go for the great. I can't teach you how to be willing to stay up late or wake up early if that is what's needed to succeed. I can't teach you how to put in extra hours that you're not being "paid" for. And, I can't teach you how to want to put in as many hours as it takes every day reading, researching, and studying on how to build the best fitness business and be the best fitness professional you can be.

My feeling is though, that if you're reading this article you already have what it takes to be great. No one is paying you to read this -- you're reading it in order to grow in some way.

What I recommend you do now is refine your "whatever it takes" attitude by focusing your energy where you need it the most.

If you don't have enough clients, focus on marketing and lead generation. If you have plenty of clients and leads, but don't retain at least 80-90% per month, then you should study up on retention based systems. And, if you're just starting out as a fitness professional and you haven't yet mastered your craft, then I suggest attending more seminars, and reading more articles on how to better train clients.

What you may not know is that the best of the best in any industry are life-long students of the game. They are in a perpetual state of learning. They're always looking to improve, which is why they always stay on top. So don't be surprised that after you master one area of your business or training that it's time to move onto another area…

The other great news about this attitude towards your profession is that you don't have to force yourself to master every area at once. You can take a deep breath and relieve some of the pressure you feel knowing that you have many years ahead of you to continue to improve.

So for now, choose one area that interests you and then learn it inside and out. After you've done that, move on to the next. This will allow you to not only accumulate knowledge, but become an expert in it, which will in turn translate into more clients, more money, and more respect within the industry.

I wish you the best of success and no matter what, never lose your attitude of doing whatever it takes in order to become successful.

Stephen Cabral has consulted for MTV, Men's Health, NutritionData, SELF, Women's Day, as well as dozens of others. He was named the PFP 2011 Trainer of the Year. He is also a fitness writer, author, studio owner, and the founder of Personal Training Business School. His free fitness business video series, proven strategies and tips can be found athttp://PersonalTrainingBusinessSchool.com