Dean Karnazes

I run with a credit card and a cell phone, so when there is not a 7-Eleven around, like some of the country roads out there, I can get him to deliver a pizza to me. And I kind of give them a coordinate, a corner.

Any goal worth achieving involves an element of risk.

I have my whole office set-up at waist level; I don't sit at all during the day. Sitting, to me, is the devil.

I do a lot of marathons as training runs. If I'm somewhere and there's a marathon, I'll sign up and just go run it.

To an extreme athlete, there's a certain appeal to doing extreme things - seeking the most extreme physical challenges in some of the most extreme climates in the world. Testing and expanding the limits of human endurance is kind of my thing.

The first thing I do when I walk into a hotel is find the gym, and if they don't have a gym, I start looking for a handhold where I can do my pull-ups. Sometimes if a shower curtain rod is sturdy enough, I'll do them there.