I swam underwater for 50 meters at a time and walked the length of the pool underwater, with a brick in each hand, all on a single breath.

If you sit there and have that mentality of 'triple down on what you're good at,' you're never going to grow. You're always going to stay the same.

I had a rough childhood coming up, and I just took all that negative energy and made it very positive for myself to drive me. I'm a very driven person. I have passion that almost scares people, just to be successful and make it no matter what.

Mental toughness is a lifestyle. It's something that you live every single day of your life. When I was growing up, I was a lazy kid. I was a lazy kid, and everybody goes, 'How did you get to where you're at today? How did you get to where you're running 200 miles at one time in 39 hours? Being so disciplined?'

The only way you gain mental toughness is to do things you're not happy doing. If you continue doing things that you're satisfied and make you happy, you're not getting stronger. You're staying where you're at. Either you're getting better, or you're getting worse. You're not staying the same.