I probably don't need to tell you that business is tough. Results don't just happen and there is no such thing as an overnight success. Sometimes it takes at least 10 years to see real success, and in many cases, it probably takes even longer than that. To hit your stride, you, the entrepreneur, need to be the one constantly guiding the ship, navigating through choppy seas and steering the company toward calmer waters.

Fellow Inc. columnist Paul Grossinger describes the entrepreneurial struggle well. "Within that reality, is what I've come to think of as the loopy roller coaster of success: some of my best rising startups have only made it - or begun to make it in some cases - after long rides without much light at the end of the tunnel at times," he writes.

Amidst all the challenge and change, it can be extremely difficult to stay focused and keep the right mindset. Self-doubt is a big challenge even though it sometimes goes publicly unacknowledged. "Entrepreneurial swagger is often a thin veneer masking crippling self-doubt, insecurity, and fear of catastrophic failure," a writer explains on Shopify's blog. "The more successful you are, the more people depend on you, and the more is at stake if you fail."

I've certainly experienced this in business over the years, but I was reminded of the intensity of these feelings while out for a run recently. It was very hot out and I was really struggling. But then I used a technique I've used frequently during tough times in business. I just started repeating a mantra, in this case: I can do this. I didn't believe it at first, but I focused on repeating it over and over. I stopped thinking about whether I could or I couldn't do the run and while repeating it, I kept going and got it done.

Why you need a mantra

Mantras are powerful. They give us words to focus on and remove us from our critical thoughts. Muhammad Ali famously used his mantra, "I am the greatest" to guide him to victory in the boxing ring. It may have sounded cocky, but when he said it with such force, everyone believed him. Of course, there were times when he lost, but his mantra was so powerful that a loss couldn't upend our image of Ali as "the greatest."

At its most basic level, a mantra is the story we tell ourselves about who we are and what we're capable of doing.

Eric Greitens, a former Navy SEAL, covers the importance of having a mantra in his book, Resilience: Hard-Won Wisdom for Living a Better Life. In an interview with the National Review, he explained why it's more important to have a mantra than a manifesto. "When we're struggling, we don't need a book in our hands. We need the right words in our minds. We need to have knowledge that we can carry with us -- not in books or in our phones, but in our hearts and our minds."

Today, it's easier than ever to find words that resonate. In fact, social media is tailor-made for this -- it's full of inspirational quotes that are tweeted, pinned, and posted. Collect the ones that resonate with you. Keep them short and simple, and curate them in a way that makes the most sense for you. Some of my favorites include: "Beauty is wherever you are at this moment"; "Believe in your vision"; "Look forward not down"; "Life is choices not destiny." Then when you find yourself in a moment of struggle, choose one and repeat it over and over. It will remove your from the struggle, and the struggle will pass.