A great run definitely involves suffering. I think any adventure athlete will tell you that there's honesty in suffering. You feel more alive than when you're just cruising along. There are moments where you have very lucid thoughts. On day four, running across the Sahara last year, I nearly passed out at mile 23 of a 28-mile stage. I was dehydrated, it was extremely hot, I had exhausted my salty foods, and I was rationing my electrolyte tablets. My ears were ringing. My head was spinning. I was seeing stars. I finally sat down in the sand and just looked around. There was no one there. And I sat there for probably 15 minutes and got in my own head and said: Don't get ahead of yourself. Be in the moment. Don't think about the race you have to do tomorrow. Just take one step. Do your best on the next step. There's magic in misery. I talked to God out there.
Karnazes, 46, won the 2008 Four Desert Challenge, a 621-mile stage race across the Atacama, Gobi, Sahara, and Antarctic deserts.