Golfing great Arnold Palmer said: "My father always said to me, 'Remember, whatever game you play, 90 percent of success is from the shoulders up.'"

Palmer has never flaunted his success as a golfer or businessman. When I visited him a couple years ago in Latrobe, Pa., I learned that although he has won hundreds of trophies and awards, the only trophy in his office is a battered little cup that he got for his first professional win at the Canadian Open in 1955. There is also a framed plaque on the wall, which explains why he has been successful on and off the golf course. It reads:

"If you think you are beaten, you are.

"If you think you dare not, you don't.

"If you'd like to win but think you can't,

"It's almost certain you won't.

"Life's battles don't always go

"To the stronger or faster man,

"But sooner or later, the man who wins

"Is the man who thinks he can."

I later discovered that this was part of a longer poem written by C.W. Longenecker. It's all about mind over matter - mental toughness.

We often hear the term mental toughness from athletes, coaches and sports commentators, but it translates to all aspects of life, especially business. Mental toughness is persevering through difficult circumstances. It is conditioning your mind to think confidently and being able to overcome frustration.

Athletes must be in tiptop physical shape, but if they don't prepare themselves just as much mentally, they will never become champions.

Serena Williams, like other top tennis players, uses her mental strength to succeed. She uses power thoughts during her matches and reviews them on changeovers, which helps her focus and get her game back on track if necessary. Her power thoughts include: "My good thoughts are powerful." "My only negative thoughts are weak." "Hang on to the thought of what you want. Make it absolutely clear." "You are No. 1." "You are the best." "You will win."

Dr. Jim Loehr of the Human Performance Institute defined mental toughness in his book "The New Toughness Training for Sports" as "the ability to consistently perform towards the upper range of your talent and skill regardless of competitive circumstances." He went on to add: "Mental toughness is all about improving your mind so that it's always on your side; not sometimes helping you nor working against you as we all know it's quite capable of doing."

Mental toughness is like a muscle. It needs to be exercised to grow and develop. You must get out of your comfort zone by taking on new tasks. As your comfort zone expands, seek out other duties to test your determination. You will soon discover that there is almost nothing you can't do if you put your mind to it. It's truly mind over matter.

Dr. David Yukelson from Penn State University lists the key characteristics associated with mentally tough elite athletes as:

- Self-Belief: Having an unshakable belief in one's ability to achieve competition goals.

- Motivation: Having an insatiable desire and internalized motivation to succeed.

- Focus: Remain fully focused on the task at hand in the face of distractions.

- Composure/handling pressure: Ability to regain psychological control and to thrive on pressure.

But in my opinion, those characteristics translate seamlessly for businesspeople in every discipline. If your mind isn't prepared to take on the challenges that constantly arise in business, you are doomed to fail. It's that simple.

Mackay's Moral: Life is 10 percent how you make it and 90 percent how you take it.

Harvey Mackay is the author of the New York Times best-seller "Swim With the Sharks Without Being Eaten Alive." He can be reached through his website, www.harveymackay.com, by emailing harvey@mackay.com or by writing him at MackayMitchell Envelope Co., 2100 Elm St. SE, Minneapolis, MN 55414.