5 things you can learn from the world's best endurance athlete

In other words, David Goggins is the modern day stoic. But unlike the ancient philosophers who advised that we should periodically embrace suffering, Goggins has actually made suffering a habit.

the point is that you have to see yourself accomplishing something before it really happens. The mind has to conceive it before the body can achieve it.

The question he asks himself in times of struggle contains only two simple words: “what if?”

When he first walked into the Navy SEAL recruiter’s office, Goggins was told that there were only 35 African-Americans in the past 70 years who had made it through. Goggins asked himself — “what if I could be the 36th? ”

Research suggests that statement – the 40% rule – has some truth. We are often physically more capable than we perceive ourselves to be. For instance, researchers found that subjects who were given a placebo but told it was caffeine were able to lift significantly more weight than those who were really given caffeine.

There’s a reserve tank within us that we never really tap on. Only by pushing ourselves to our limits — and then breaking them — can we reach our full potential.

To understand your “why” and what motivates you, “you first have to spend time alone,” he adds, especially in today’s fast-paced environment. “Everybody’s walking around looking at their phone. … They go home and flip through channels. They go home and talk on the phone. How are you going to figure out your purpose if you haven’t figured out, first, in a quiet space, what you need to do?

“The world is moving too fast. You have to slow it down and gain control.”

Goggins intimately understands how we hold ourselves back by telling ourselves we are incapable. He grew up in an abusive home where his father beat him up, was bullied at school, stuttered and was, at one stage, obese. The first time he ran, he made it only 400 metres. "I saw myself as the weakest man on the planet," Goggins reveals, "and I wanted to change that. Instead of making it 'woe is me'... I changed my thought process."

most of us spend our lives trying to avoid pain, whereas David seeks it out. He believes that you can’t possibly reach your true potential without truly pushing your limits. To get there will take some tough challenges and, yes inevitable pain. Enjoy it, embrace it even. The pain is a reminder of your hard work.